Noah Shachtman of Wired News (who just got back from Iraq) says,

You might think your anonymous online rants are oh-so-clever. But they'll give you away, too. A federally-funded artificial intelligence lab is figuring out how to track people over the Internet, based on how they write.

The University of Arizona's ultra-ambitious "Dark Web" project "aims to systematically collect and analyze all terrorist-generated content on the Web," the National Science Foundation notes. And that analysis, according to the Arizona Star, includes a program which "identif[ies] and track[s] individual authors by their

writing styles."