He has a Member-user on his tracker, even I have power-user, or something like that.
Donators also have some tag there.
Donater's get a green euro symbol beside there name, Force is the best example. Unless he donated anonymously.
And the server bill's cost around 415 euros for three months. I wonder how he could have donated $1500, unless he is counting the donations in multiple transactions and at a max 20 euro per transaction I wonder how many times he has donated, and not once his name was on the donation graph, even though I don't like pointing fingers, the fact that he donated that much doesn't seem to be true.
EDIT: Damn fast replies, there were 5 new replies through the time I typed this