Going to jail for crimes in other countries

Scenario:
I write decryption software for a hobby. In Canada, my hobby is quite legal and I don't hide what I do.
Meanwhile, an American company encrypts their product in such a way that my decryption software opens it.
As the resident expert on decryption techniques, I get invited to an American computer show to speak. I show up, and U.S. authorities slap me in chains and throw me in jail, despite the fact that I have never used decryption software in an illegal fashion while on American soil.

I believe that's the scenario surrounding this story:
http://www.sfgate.com/cgi-bin/articl...2/BU206051.DTL

Follow up: the accused actually had a hard time getting a visa to get back in to the U.S. so he could show up at the court case.