Would double jeopardy even apply here? Isn't it about the govt's ability to try someone more than once for the same crime? There doesn't seem to be any constriction on private citizens' ability to continue suing someone over and over, if some of the cases here on TD are any indication.
I'm Canadian, so I don't have a dog in the hunt, but I've always found Ron Paul honest and admirable. Still, it does seem out of character for him to sue. The only reason I can see to go ahead with this suit is to possibly unmask the uploaders as being connected with Jon Huntsman himself (there is some evidence).