From a single detection of one hostile email you can often expand the picture to many mail recipients. A little open source research identifies the common community the recipients belong to. It's pretty straight forward.
Mike ------Original Message------ From: Nathan Eisenberg To: nanog@nanog.org Subject: RE: more news from Google Sent: Jan 13, 2010 12:53 PM > -----Original Message----- > From: Leo Bicknell [mailto:bickn...@ufp.org] > Sent: Wednesday, January 13, 2010 12:49 PM > To: nanog@nanog.org > Subject: Re: more news from Google > > It's not clear to me you have to read any e-mail to figure out that > "help_us_free_ti...@gmail.com" might be someone who's taking a > political position. A search company may also, say, look for e-mail > addresses listed on the web sites that must be censored, and when it's > the same list being hacked, draw a conclusion. It's also possible that far less questionable means are being utilized. Perhaps there are a sufficient number of pro-free-speech'ers at Google.cn (which is presumably largely composed of Chinese nationals) that are privy to such information. It only takes one guy going "hey! I know some of these email addresses!"... Nathan Sent on the Sprint® Now Network from my BlackBerry®