Because he's a journalist who's being unjustly pursued for revealing the US government's dirty secrets. Secrets such as: American helicopter pilots gunned down two Reuters journalists in Iraq, and then killed a random civilian who came across and tried to rescue one of the wounded journalists. The pilots shot up a van with kids in the process (thank God the kids survived, though they lost their father), and then joked and laughed about it. The military covered it up.

The US is trying to set the precedent that if you air our dirty laundry, we can go after you, wherever you are in the world. Not in the US? No problem. Not an American? No problem.