Remember the movie "Sex, Lies and Videotape"? I invoke its poetic meter to frame a discussion of civil action privacy law. Type 4, you will recall, involves civil actions, individuals against individuals, in state court actions known as "torts." These laws, famously framed out of a 1890 law review article, were the first time the term "privacy" came directly into named U.S. laws. Putting on my historian's hat, I have argued that this occurrence was not the result of a notion of privacy being "discovered" -- notions of privacy date back to ancient times in Western Culture, and the term itself is derived from Latin -- but because modern, urban, industrial society at the turn of the last century, driven largely by technological developments, not the least of which was photography, encroached so significantly on cultural mores that the law was called upon as a defense to shore up those norms. 
Privacy torts such as "invasion of privacy," "misappropriation of likeness," "intrusion upon seclusion" and "false light" -- cousins to the older torts of defamation, libel and slander -- did not fare well in the twentieth-century for three reasons. The first is that First Amendment principles caused them to be interpreted in a highly restrictive manner. The law set a high legal bar by which one could see a claim through to damages. The second is that by and large these actions became the privilege of famous people and were not readily available to the common man or woman. Misappropriation of likeness was something that a famous person such as a movie star whose likeness was readily recognizable could claim was being used, for example, to sell toothpaste with no permission from, and no remuneration for the star. Third, although U.S. law designed civil procedure to be available to "everyman," the cost to entry has often belied that aspiration. Under the British system, the loser pays attorney fees for both sides. U.S. law has a default that allocates fees to each party, win or lose. Thought to be fairer, those fees nonetheless remain an obstacle, and with the law not favoring plaintiffs in these cases, plaintiff lawyers without retainers working on percentage had little incentive to take on the cases.
The Internet era has simultaneously created a fertile landscape for these kind of actions and a new barrier to action. The fertile landscape rests in the scope and amplification that the Internet offers speech. Without it, an invasion of privacy, for example, or slander, might fall upon deaf ears or be confined to such a small community that its staying power in terms of actual damage to the person -- emotional or financial -- would be difficult to access in the fact-driven environment of the courtroom and its rules of evidence. With it, we not only have speech, we have endurance for all time, international scope and the potential for reverberation of that invasion or libelous statements have to do real damage to people in terms of lost employment, emotional and reputational harm. On the other hand, the Internet would appear to offer technological anonymity. Not knowing who your defendant is makes it difficult to sue, and section 230 of the Communications Decency Act, that protects I.S.P.s from this kind of claim, reinforces a potential plaintiff's frustrations. While not entirely impossible to realize, real anonymity remains largely a sham, however, as the Petraeus case demonstrates. Notwithstanding efforts to hide, both Broadwell and Petraeus were easily discovered with sufficient sleuthing. More than any other example in the history of the Internet, this case demonstrates the extraordinary efforts that a user must undergo not to be found. (For information on technical tips, see this article. ) Flip the insight around in light of our discussion and one recognizes that a potential defendant can be identified. Viola! Now U.S. law only needs to instantiate for everyone the same degree of legal and technical process that Ms. Kelley received as a preferred customer of the F.B.I.
I did not need the likes of campus gossips sites to recognize that the Internet offers privacy torts growth potential, but working with many students and their parents on these matters ramped up awareness. More and more cases of this ilk are emerging. Now that the public, including victims of these actions and the tort bar, see the possibility of successful actions, watch the growth industry. And by the same token, watch what you say on the Internet for that same reason. You don't have to be Michael Jackson or Liz Taylor, anyone can sue. And you don't need to The Inquirer to be on the other side of the equation either, just on the Internet.