> Besides capitalists and thieves, there were those how emigrated
> for religious reasons.

But mind you--most of these "thieves" weren't actually felons.
Check out the new book by Scott Christiansen: "With Liberty for
Some: 500 Years of Imprisonment in America", Northeastern
University Press (reviewed in the February 13 issue of the
Economist, Review of Books & Multimedia).  In short, many
prisoners the "land of the free" relied on for forced labour on
plantations, etc. were actually simply kidnapped street kids from
London.  One of the big winners of this system by the way was.  
So, i'd add the kidnapped to your list :)