In this case I see both violations of False Light and Appropriation being possible, if these guys didn't do anything, and didn't agree to be involved in this stunt.
Personally I like the idea of vigilantism, but these things are better left to law enforcement and the legal system. They are in place for a reason, after all.
You know that that Wikipedia article doesn't even have the word "anonymity" in it, right?
There's no general privacy law in the U.S. There's some minor right to write anonymously, extrapolated from the First Amendment, but absolutely no right to be anonymous in general, and in fact the First Amendment goes the other way: Threadless has the right to publish those photos and to make any truthful statements about them whatsoever. In many cases Threadless can even make untruthful statements about the photos and still be perfectly legal.
Maybe I'm misreading Wikipedia, but it looks like False Light and Approbation violations would require (respectively) the dissemination of false information or some intent to gain financially.
However, it's probably true that these laws will be tested in unexpected ways as everyone gains the power to communicate with "the public".
Check the privacy laws of the United States - they clearly do protect our right to anonymity: http://en.wikipedia.org/wiki/Privacy_laws_of_the_United_Stat...
In this case I see both violations of False Light and Appropriation being possible, if these guys didn't do anything, and didn't agree to be involved in this stunt.
Personally I like the idea of vigilantism, but these things are better left to law enforcement and the legal system. They are in place for a reason, after all.