Just who's responsible (beyond a Chinese-speaking entity) isn't clear, since the culprits have gone out of their way to hide their tracks. Lacoon suspects that the Chinese government may have crafted Xsser to snoop on protesters, but there's also a chance that criminals are using the hostile code to look for accounts they can steal. The malware isn't likely to be all that effective no matter who's at fault, especially among cautious types who've already switched to secure messaging software. Still, it's not exactly comforting for activists who already have plenty of reasons to be suspicious.

[Image credit: Chris McGrath/Getty Images]