How do you deal with a rude player in DF?

[File2ish]

Depends on the situation.

If I'm the target of the abuse (which so far I haven't been): I won't heal them immediately (unless it's the main tank, he doesn't get healed everyone loses). I'll humor them/argue with them, make them look bad. I'll never leave though, that's just being a prick to everyone else.

If I'm not the target and the target is being unjustifiably attacked (example: first timers watching cutscenes in CM and/or Praetorium): I defend them. Give tips when needed (like for first timers).

If they are justifiably being attacked (example: person intentionally not doing their role) I'll generally stay silent and hope it blows over with no one leaving the party so we can get on with the duty.