[qwerty_asdf]

According to a Scientific American article [1], he was aged 54 in early 2008, so that puts him at roughly 60 years old, depending on his precise date of birth...

[1] http://www.sciam.com/article.cfm?id=self-experimenter-free-f...

[dm2]

According to the link below he was 52 in 2005.

http://www.nytimes.com/2005/09/11/magazine/11FREAK.html?page...

[ekianjo]

Any idea why his year of birth does not seem to be publicly known ?

[judk]

Because no one posted that trivial detail, and he didn't share it on Facebook?