Griefing is people being complete and utter assholes, which can be expected almost anywhere. The goal of any griefer is to make the target Ragequit.
Some easy and fun ways to do this is to:
- Toss grenades everywhere. (Any Port and the Cube Hotel are especially fun)
- Kill specific people repeatedly.
- Rape the corpse of the people you kill.
- Make porn featuring the rape of the corpse of the person you kill.
- Constantly page them.
- Emote them repeatedly.
- Offer to buy their weapon or armor, knowing full well you can't equip it/would do no damage.
- Whine when they don't sell it.
- Whining in general.
Remember, repetition is key.