Is Airliners legal?

A question occured to me tonight, and I wondered about it hard. Is Airliners.net legally able to sell pictures of aircraft? All of the logo's are copyrighted, even the ones on the racers and small private planes, not just airliners. So how do they get away with it? I really don't see them being able to pay royalties to every airline or racing team, GA manufacturer or private owners, so what gives?