That depends on the kind of abuse.
If you feel that you're being spammed by another member, let us know ASAP and we'll take care of it. General fighting falls into the grey areas, though, and we won't intervene with a fight unless it's immediately necessary.
If the fight is taking place out in the open on public threads, it's fairly likely that you'll BOTH be in trouble no matter where the "finger" is being pointed. If it's happening via PMs, we will only step in if it becomes clear that the conflict is one-sided and is, indeed, abuse. Off-site methods of communication we have no control over, so if something is happening elsewhere, you're on your own. Sorry.
Finally, when reporting abuse, please send a PM to a mod or myself and give us a full report of what's happening. We can't help you if we don't have details.