Bruce Schneier could probably find out just about everything about you without breaking a sweat. He has built a career out of discovering weaknesses in computer systems and has analyzed security flaws in everything from biometrics to post-9/11 airline security. The designer of the popular Blowfish and Twofish encryption algorithms (the latter was a finalist for the Federal Advanced Encryption Standard), he has even earned a namecheck in The Da Vinci Code. Schneier is also the founder and C.T.O. of BT Counterpane, which calls itself “the world’s leading protector of networked information.”
In addition to writing a popular security newsletter and a blog, Schneier has also written a slew of books on the subject, including the seminal Applied Cryptography, Secrets and Lies, and his latest, Beyond Fear: Thinking Sensibly about Security in an Uncertain World.
He has kindly agreed to field your questions. Just keep in mind that even if you ask anonymously, he can probably figure out who you are.
Addendum: You can read the answers to these questions here.