Its MUCH harder to pirate an MMO - depending how much is held on the server backend... its pretty much dependant on someone either coding an entire server backend from scratch or leaking the official one - which means that its rarely updated and often buggy/broken.
No less buggy/broken than the official servers imo. Besides, its pretty irrelevent. Its obvious that MMOs are hard to pirate because most of everything is held on the official servers and you need to connect to them. They have problems of there own to deal with. You can't simply try and make an offline game and apply MMO logic to it, it simply won't work.

