Bit of an aside story but I'm in the process of renewing a US work Visa (travel into the US for work often from Canada). I was reminded going through the online form last week that there are 3 full pages of questions like: "Have you ever participated in child trafficing?", "Have you participated in terrorist activities?", "Have you participated in overthrowing a government?", etc. etc. All of the most extreme international crimes you could think of.

I later realized that they don't expect any one to answer these truthfully, however if in future you are caught doing (Edit: or having previously done) any of these things the "lied on Visa application" is grounds for an instant revocation of the Visa without all the other possible complications.