Just picking up a discussion leaving off from another thread (because there's too much there to split off). If anyone wants to read up, you can see what has been posted starting about here and going through about page 7.
I just want to add my copper pennies to the discussion:
My view of it: coming into a game like Salem is like going to play poker at a card room. If you don't know the game, don't cry when you lose all your money by the end of the night. The same thing applies to Salem (and other open PvP games like it). If you don't know how to handle yourself and at least avoid the worst of it, even if you don't know the specific game, you voluntarily decided to go swimming with the sharks. No crying when you get bit!! Does it really matter if the other guy can be labelled as a "griefer", "raider" or he/she was just policing and protecting his home territory you just happened to wander into?
There's an acronym from EVE I fell in love with, "NBSI"--"Not Blue? Shoot It!". In other words, if you're not a known ally (colored blue in EVE), expect to get attacked by anyone you see, and you should be prepared to do the same to anyone you run across near your home. Doesn't mean you have to, just be prepared. The guy that gets attacked really won't know why unless you tell them. Even then, as far as they're concerned, you're just another big, bad griefer. I refuse to use the term "victim" because A) it's a game and B) you choose to be here and what you do in the game has consequences no matter how innocuous it seems. Just as a note: some groups had just the opposite position--don't fire unless it's a known enemy--known as "NRDS," "Not Red? Don't Shoot!"
In summary: a raider isn't always a griefer, though griefers might be raiders. If I were to draw a Venn diagram, there would be two interconnecting circles, not one inside another or both completely overlapping.