There were reported cases already where so-called safe sites became infected. We're living in a real world where there's no perfect security. A very skilled malcoder can infect sites like MT, Wilders, and others. But like I said, getting infected through these sites is a very slim chance because, like you said, they are "heavily fortified".I believe sites like MT, Wilders Security Forums and BleepingComputer are heavily fortified, right? Don't believe ask the admins.
Any if any gets infected it'll shut down immediately. So surfing them without security software is SAFE