Per wikipedia: "A griefer is a player who does things in a game to deliberately cause annoyance ("grief" in the sense of "giving someone grief") for the griefer's own enjoyment. Such a player is a particular nuisance in online gaming communities."
In my experience as an RPer, these nuisances do occur. here are some tips for dealing with one.
-If you are on the same faction, you can whisper them and politely ask them to stop.
-If you are on a different faction and know someone on that faction you can ask them to tell the person politely to stop.
-If the person does not not stop, report them.
-If needed move to a different location, in some cases they may follow, definately file a ticket.
Per Blizzard's harrsasment policy (http://us.battle.net/support/en/article/harassment-policy):
This category includes language and/or actions intended to disturb groups of players or areas of the world, such as:
-Disruption of player sponsored events or gatherings.
-Excessive use of in-game sounds or visuals. Excessively casting spells with noticeable effects in crowded areas.
-Impeding or blocking access to an NPC, doodad, doorway, or any other area of the world that a player would normally be able to access.
With all that in mind SoE is an RP realm, if you do not RP, please try and be respectful to those that do. For those in non RP guilds and see a member doing something that could be considered griefing, please ask them to stop.
If anyone else has any other tips to add please do. And happy RPing to those that do.