Design, Construction, and Applications of a High-Resolution Terahertz Time-Domain Spectrometer

This thesis reports on the design, construction, and initial applications of a high-resolution terahertz time-domain ASOPS spectrometer. The instrument employs asynchronous optical sampling (ASOPS) between two Ti:sapphire ultrafast lasers operating at a repetition rate of approximately 80 MHz, and we thus demonstrate a THz frequency resolution approaching the limit of that repetition rate. This is an order of magnitude improvement in resolution over typical THz time-domain spectrometers. The improved resolution is important for our primary effort of collecting THz spectra for far-infrared astronomy. We report on various spectroscopic applications including the THz rotational spectrum of water, where we achieve a mean frequency error, relative to established line centers, of 27.0 MHz. We also demonstrate application of the THz system to the long-duration observation of a coherent magnon mode in a anti-ferromagnetic yttrium iron oxide (YFeO3) crystal. Furthermore, we apply the all-optical virtual delay line of ASOPS to a transient thermoreflectance experiment for quickly measuring the thermal conductivity of semiconductors

Inherently Dangerous: The Potential for an Internet-Specific Standard Restricting Speech That Performs a Teaching Function

Real or not, we perceive the convergence of several dangers-the physical threat of terrorism, both foreign and domestic; the economic threat of recession, corporate scandal, and globalization; and the social threat of new technology that connects, informs, exposes, and overwhelms us. At this moment, certain First Amendment protections are ripe for circumscription. The question, then, is whether our constitutional right of free speech is relative and conditional. The populist answer is yes. The legal answer is much more complicated. To that end, this Article carries three goals. The first is to highlight parallel signals from the three branches of government suggesting that dangerous instructional speech will no longer be tolerated or constitutionally protected. The legislative branch has recently criminalized speech that is understood to promote criminal activity by teaching or demonstrating its methods. The executive branch undertook the first prosecution under this recent statute and instituted new investigative guidelines and procedures designed to aid enforcement of these provisions. Finally, the judicial branch recently signaled its willingness to consider exempting instructional speech from full constitutional protection. Building on this last point, the second goal of this Article is to establish that the Supreme Court may be poised to announce a new theory of lesser constitutional protection for dangerous instructional speech. Here, I suggest that the Court will likely explicitly limit the scope of Brandenburg v. Ohio, distinguishing and exempting speech that, through its capacity to perform a teaching function, creates the abstract potential for violence. In its place the Court seems inclined to adopt a derivative of the public danger doctrine more akin in application, albeit unintentionally, to a discredited analysis used primarily to sanction political censorship of the Socialist Party in the 1920s and of the Communist Party in the 1950s. Brandenburg\u27s imminence requirement is eliminated as applied to certain types of instructional speech under this approach. The question of public danger, both as a matter of doctrine and proof, will become a function of the speech itself and the context of its distribution. Intent, a question of fact, may be consumed by the scope of the public-danger analysis. The third and final goal of this Article is to demonstrate that this public-danger derivative will, in application, create a de facto Internet-specific standard, incorporating standards of likelihood and intent that are easily subsumed by the very nature of the network and that will tend to affirm content-based regulation of disfavored online speech that performs a teaching function

The Failure of the Rule of Law in Cyberspace: Reorienting the Normative Debate on Borders and Territorial Sovereignty

The ultimate goal of this article is to suggest a different perspective on the issue of extraterritorial regulation in cyberspace. Between 1996 and 2002, over the course of several law review articles, professors David R. Johnson, David Post, and Jack L. Goldsmith engaged in a highly influential debate addressing the significance and legitimacy of physical, geographically-defined borders and territorial sovereignty in the regulation of cyberspace. At bottom, it was a contest between internal or indigenous regulation and the imposition of existing external regimes. At its heart lay two overarching areas of disagreement: First, descriptively, whether and to what extent the architecture of the Internet is borderless or boundary-destroying, so as to be resistant to regulatory regimes grounded in territorial authority; and second, normatively, whether and to what extent a nation may legitimately exercise its regulatory power extraterritorially, particularly in the context of online activity. Initially, this seemed a robust debate. But it narrowed predictably. The descriptive issue moved from platitudes of the Internet\u27s inherent nature to a contest of choices and predicted technological advancement. The normative question became fundamentally a disagreement about the origins and limits of sovereign power, particularly as related to the regulation of extraterritorial activities having local effects, as well as the spillover effects of such regulation. Related to this fundamental question, and particularly relevant here, the participants ultimately disagreed as to the legitimizing effect of jurisdictional and choice-of-law principles; i.e., whether these jurisprudential mechanisms for resolving regulatory-overlap disputes adequately limit and resolve multiple, simultaneous, and competing claims of unilateral, extraterritorial regulatory power. This pushed the discussion back to the descriptive; to questions of functional identity, scale, effects, and (somewhat tangentially) consent. And here, it seemed to wither. This article acknowledges these debates and their importance, but suggests that by framing the argument as they did, their authors - particularly Johnson and Post - were pressed to untenable assertions that fatally undermined their position. Seeking to avoid a similar fate, here the underlying issues are approached from a slightly different perspective. Jurisdictional and choice-of-law principles are recognized, fundamentally, as expressions of the rule of law; devices by which conformity to the rule of law is to be actualized. But the term the rule of law has recently become so commonplace and pedestrian that its precise connection to these principles may be lost. Indeed, at times in their debate, professors Johnson, Post, and Goldsmith seem to talk around the rule-of-law concept, failing to step back to adequately examine the purposes, values, and virtues of law from which their arguments might ultimately flow. My intent is to reestablish this link through consideration of the more fundamental question; whether the governance of cyberspace by traditional laws, imposed by territorially-based sovereigns, conforms to the rule of law. I conclude that the imposition of territorially-based regulatory regimes in the governance of cyberspace fails to conform to the rule of law. But this is not the end of the inquiry. For if the rule of law fails in cyberspace, what then? Must we reform or recreate our regulatory system, or is conformity with the rule of law a less important virtue of legal systems than popular rhetoric might suggest? I begin in Section I by outlining the normative debate on the governance of cyberspace, borders and territorial sovereignty, focusing on the Johnson-Post-Goldsmith debate. I then seek to identify weaknesses in this approach. This provides a foundation upon which to reframe the debate in Section II, moving from a focus on the validity of sovereign power and its limits, to the relationship between individual autonomy and the purposes, values and virtues of law. Here, the central question is whether the governance of cyberspace by traditional sovereign legal systems conforms to the rule of law. Answering this question in the negative, Section III asks simply, what then? Is conformity to the rule of law a prerequisite of authority or simply one value among many, to be weighed against other values served by law and promoted, but without such exaggerated importance that it devalues other laudable social goals

Section 230 of the CDA: Internet Exceptionalism as a Statutory Construct

Since its enactment in 1996, Section 230 of the Communications Decency Act has become perhaps the most significant statute in the regulation of online content, and one of the most intensely scrutinized. The essay begins with a brief introduction to Section 230. As interpreted and applied by the judiciary, this statute is now conceived as a broad grant of immunity from tort liability.—broad not only in terms of those who can claim its protection but also in terms of predicate acts and causes of action to which such immunity extends. Working from this foundation, I then seek to position the courts’ expansion of Section 230 immunity within the larger debate over Internet governance, suggesting that proponents of expanded immunity are successfully creating what might be characterized as a modified, less demanding form of cyber-libertarian exceptionalism than what Eric Goldman calls, in his essay in this book, the “First Wave of Internet Exceptionalism.” (one of “Internet Utopianism”), as articulated in the mid-1990s. The dramatic expansion of Section 230 immunity has in a limited sense effectuated a vision of a community in which norms of relationship, thought and expression are yet to be formed. The tort liability from which Section 230 provides immunity is, together with contract, a primary means by which society defines civil wrongs actionable at law. In the near absence of these external norms of conduct regulating relationships among individuals, the online community is free to create its own norms, its own rules of conduct, or none at all. It is a glimpse of an emergent community existing within, rather than without, the sovereign legal system. Finally, I make the case for preserving broad Section 230 immunity. As an initial matter, many of the reforms offered by commentators are both unnecessary and unwise because the costs of imposing indirect liability on intermediaries are unreasonable in relationship to the harm deterred or remedied by doing so. Moreover, the imposition of liability would undermine the development of Web 2.0 communities as a form of modified exceptionalism that encourages the development of communal norms, efficient centers of collaborative production, and open forums for communication

The Failure of the Rule of Law in Cyberspace: Reorienting the Normative Debate on Borders and Territorial Sovereignty

The ultimate goal of this article is to suggest a different perspective on the issue of extraterritorial regulation in cyberspace. Between 1996 and 2002, over the course of several law review articles, professors David R. Johnson, David Post, and Jack L. Goldsmith engaged in a highly influential debate addressing the significance and legitimacy of physical, geographically-defined borders and territorial sovereignty in the regulation of cyberspace. At bottom, it was a contest between internal or indigenous regulation and the imposition of existing external regimes. At its heart lay two overarching areas of disagreement: First, descriptively, whether and to what extent the architecture of the Internet is borderless or boundary-destroying, so as to be resistant to regulatory regimes grounded in territorial authority; and second, normatively, whether and to what extent a nation may legitimately exercise its regulatory power extraterritorially, particularly in the context of online activity. Initially, this seemed a robust debate. But it narrowed predictably. The descriptive issue moved from platitudes of the Internet\u27s inherent nature to a contest of choices and predicted technological advancement. The normative question became fundamentally a disagreement about the origins and limits of sovereign power, particularly as related to the regulation of extraterritorial activities having local effects, as well as the spillover effects of such regulation. Related to this fundamental question, and particularly relevant here, the participants ultimately disagreed as to the legitimizing effect of jurisdictional and choice-of-law principles; i.e., whether these jurisprudential mechanisms for resolving regulatory-overlap disputes adequately limit and resolve multiple, simultaneous, and competing claims of unilateral, extraterritorial regulatory power. This pushed the discussion back to the descriptive; to questions of functional identity, scale, effects, and (somewhat tangentially) consent. And here, it seemed to wither. This article acknowledges these debates and their importance, but suggests that by framing the argument as they did, their authors - particularly Johnson and Post - were pressed to untenable assertions that fatally undermined their position. Seeking to avoid a similar fate, here the underlying issues are approached from a slightly different perspective. Jurisdictional and choice-of-law principles are recognized, fundamentally, as expressions of the rule of law; devices by which conformity to the rule of law is to be actualized. But the term the rule of law has recently become so commonplace and pedestrian that its precise connection to these principles may be lost. Indeed, at times in their debate, professors Johnson, Post, and Goldsmith seem to talk around the rule-of-law concept, failing to step back to adequately examine the purposes, values, and virtues of law from which their arguments might ultimately flow. My intent is to reestablish this link through consideration of the more fundamental question; whether the governance of cyberspace by traditional laws, imposed by territorially-based sovereigns, conforms to the rule of law. I conclude that the imposition of territorially-based regulatory regimes in the governance of cyberspace fails to conform to the rule of law. But this is not the end of the inquiry. For if the rule of law fails in cyberspace, what then? Must we reform or recreate our regulatory system, or is conformity with the rule of law a less important virtue of legal systems than popular rhetoric might suggest? I begin in Section I by outlining the normative debate on the governance of cyberspace, borders and territorial sovereignty, focusing on the Johnson-Post-Goldsmith debate. I then seek to identify weaknesses in this approach. This provides a foundation upon which to reframe the debate in Section II, moving from a focus on the validity of sovereign power and its limits, to the relationship between individual autonomy and the purposes, values and virtues of law. Here, the central question is whether the governance of cyberspace by traditional sovereign legal systems conforms to the rule of law. Answering this question in the negative, Section III asks simply, what then? Is conformity to the rule of law a prerequisite of authority or simply one value among many, to be weighed against other values served by law and promoted, but without such exaggerated importance that it devalues other laudable social goals

A Third-Party Doctrine for Digital Metadata

For more than four decades, the third-party doctrine was understood as a bright-line, categorical rule: there is no legitimate privacy interest in any data that is voluntarily disclosed or conveyed to a third party. But this simple rule has dramatic effects in a world of ubiquitous networked computing, mobile technologies, and the commodification of information. The digital devices that facilitate our daily participation in modern society are connected through automated infrastructures that are designed to generate vast quantities of data, nearly all of which is captured, utilized, and stored by third-party service providers. Under a plain reading of the third-party doctrine, the substantial majority of that data receives no Fourth Amendment protection—no matter how sensitive or revealingIt is generally agreed that the balance struck in the third-party doctrine is no longer reasonable, as it fails to account for the far greater degree of privacy intrusion occasioned by warrantless government access to all of this personal data. Acknowledging that current approaches fail to adequately account for rapid advancements in information technology and analytics, the Supreme Court has responded in several recent cases by creating specific, narrow exceptions to the third-party doctrine for certain devices and data. But in the absence of a more generalized and coherent approach, lower courts have struggled to understand and apply these cases to other technologies and types of data, leading to uneven and often contradictory results.This Article provides a new analytical framework for adapting the third-party doctrine to the new information environment. Drawing on the Court’s recent decisions, the Article advances a three-step approach for the development of workable, bright-line rules governing the search and seizure of different categories of data. It identifies both guiding principles and competing interests, as well as the specific factors to be considered in assessing the legitimacy and relative strength of those interests. It then explains the relationship between these factors and their role in the balancing process that produces appropriate and workable rules. The goal is to provide a consistent, practical framework to be applied more generally across the different categories of data generated by digital technologies and services

In Defense on Online Intermediary Immunity: Facilitating Communities of Modified Exceptionalism

In the ten years since its enactment, Section 230 of the Communications Decency Act of 1996 (CDA) has become perhaps the single most significant statute in the regulation of online content, and one of the most heavily criticized. Many early commentators criticized both Congress, for its apparent inability to craft the more limited statute it intended, and the courts, for interpreting the statute broadly and failing to limit its reach. Later commentators focus more clearly on policy concerns, contending that the failure to impose liability on intermediaries fails to effectuate principles of efficiency and cost avoidance. This article takes the opposing view, in defense of broad Section 230 immunity. It argues that the immunity provisions of Section 230 play a significant role in broader questions of Internet governance. Specifically, Section 230 immunity provides a means of working within the sovereign legal system to effectuate many of the goals, ideals and realities of the Internet exceptionalism, cyberlibertarian movements. By mitigating the imposition of certain external legal norms in the online environment, Section 230 helps to create the initial condition necessary for the development of a modified form exceptionalism. With the impact of external norms diminished, Web 2.0 communities, such as wikis and social networks, have emerged to facilitate a limited market in norms and values, and to provide internal enforcement mechanisms that allow new communal norms to emerge. Section 230 plays a vital role in this process of building heterogeneous communities that encourage collaborative production and communication. Efforts to reform or restrict Section 230 immunity are therefore unnecessary and unwise

A Cognitive Theory of the Third-Party Doctrine and Digital Papers

For nearly 200 years, an individual’s personal papers enjoyed near-absolute protection from government search and seizure. That is no longer the case. With the widespread adoption of cloud-based information processing and storage services, the third-party doctrine operates to effectively strip our digital papers of meaningful Fourth Amendment protections. This Article presents a new approach to reconciling current third-party doctrine with the technological realities of modern personal information processing. Our most sensitive data is now processed and stored on cloud computing systems owned and operated by third parties. Although we may consider these services to be private and generally secure, the law does not currently require the government to obtain a warrant to access our information. The third-party doctrine creates a sweeping exception to the warrant requirement for any information exposed to a third party—even where that third party is an automated computing system rather than a human. As a result, our personal papers now receive no more protection than any other piece of potential evidence. In practical terms, they receive less. This ahistorical approach undermines the essential balance between an individual’s interest in privacy and the public’s interest in law enforcement. Many have identified and tried to rectify the privacy problems created by this shift, but it has proven difficult to articulate a limitation to the third-party doctrine that is both consistent with existing principles and feasible in practice. The Article begins with the intimate connection among freedom of thought, privacy of thought, and the longstanding enumeration of “papers” as a distinct object of Fourth Amendment protection. This historical understanding, which prior generations recognized intuitively, now finds strong support in contemporary cognitive science. Modern models of human cognition reveal how papers serve as cognitive artifacts performing cognitive tasks. These models furnish a set of proxy characteristics for reliably singling out those personal papers whose protection would most likely serve constitutional values. The result is a coherent and workable method for bringing needed discipline to the third-party doctrine and restoring equilibrium to information privacy