Griefing is singling out a specific player and following him around, killing him whenever he rears his head. Or using social engineering to gain access to a guys starship fleet and then selling it. Or locking down a newbie area with ridiculously over-leveled characters preventing them for accomplishing anything or even escaping. Or taking advantage of bugs/broken mechanics to gain advantage over other players in a way never intended by the devs.

This is just retarded PVP.