The slimeball reporters at the LA Times used FR's own search engine to comb through everything he's posted here in the past three years. There were little personal details that leaked out here and there in his posts. The lunatic left-wing fringe enjoys using them as weapons.
LEt's all be careful out there.
They found out using the same techniques of investigative journalism that Dan Rather should have used in vetting the forged documents.
It's not very hard to deduce someone's identity online if you set your mind to it, which is one of the reasons I don't bother to conceal mine, and haven't for the past 20 years.