EVE Online, recently posted an interesting blog that discusses problematic players and the responses to their behavior -- one that exposes a fundamental misconception players have about the GMs who enforce the rules.
Wyand's main point, though perhaps a bit too easy to misconstrue, is that being a jerk in most games is not against the rules. There is a big difference between threatening someone's life and hurting someone's feelings when it comes to enforcing chat violations or actioning players, and those who choose to offer up personal information about themselves must be aware that certain unsavory individuals will be happy to use it as a weapon at the first available opportunity.
The full post is worth a read and includes some real-life examples of complaints Wyand received while manning CCP's support desk. It's worth noting, of course, that every game company has its own set of rules when it comes to harassment; what brings down the banhammer in RIFT might not even be a blip on the radar of a World of Warcraft GM.