I've wondered this as well, from my understanding they did blacklist all of the well known exchange/ico addresses... I always wanted to ask what's stopping these people from movinvg their coins to different addresses? Of course, if people have a loophole to take advantage of, they will.
If exchanges move their customers BTC from wallets, the customers have far bigger problems then missing free byteball..
Other than that, tony has heuristics to detect exchange addresses (number of transactions).
BTC whales get a lot of Bytes, that is true.