I went to school with Mark since elementary school and I can assure you this is all a joke and he doesn't hate the US government at all. Mark was just one of those kind of weird kids. He taught himself Arabic, was obsessed with weapons, and had interesting ideas about government...signs, I admit, he may share with a terrorist. But look at the kid...he's a tiny little guy and he's not a fighter at ALL. Also, the yearbook comments you may have heard about were not the first signs of his plans. He has talked crazy like that all his life. If he were serious the whole time, this has been planned since he was a little kid. This kid is a genius, by far the smartest kid I've ever met in my life...he's plenty clever enough to avoid apprehension and he would not admit anything. So far, Mark hasn't done much...he's made a few comments on websites and supposedly was leaving to buy weapons. (1) Mark is one of those weird kids who would get amusement out of making such comments...just to get people talking, just for some attention, and just to make himself laugh. (2) $2100 isn't much money and the only evidence so far of Mark going to buy weapons is his comments...which were probably just another attention-grabbing comment. He was LAUGHING when he was cuffed up & walking to jail. This is just thoroughly amusing to Mark. Also, Mark had interesting plans about government and the US wasn't his plan, but he never expressed ANTI-American sentiments. He's disagreed with US pursuits and choices, but he's just not one of those psycho terrorists. He's just a different kind of kid who was interested in weird things. This is all just a little joke...
OK, since you know him. But he had better be careful about what he jokes about, because it might be like saying "bomb" as you are checked for a flight.