Foodstamp, "carebear" is an old phrase from the PBM Diplomacy community (Diplomacy is a board game first published in 1959, and there weren't that many MMO's around then). As Squirrel above already defined, it means a person who freaks out when somebody backstabbs them. Actually, the word "carebear" is a derviate from the phrase "carebear allies", ie two (or more) people who stuck together from game to game, co-operating and looking after each others backsides (effectively playing as a team against the other players) then voted for a draw when just they two were left; it affected the Diplomacy ladder heavily in the 80's (and even in the 90's even though different rule-sets had been defined to prevent care-bears from ruling the ladder).
I don't know if the MMO carebear is a derivate from the Diplomacy carebear (in MMO's carebears are AFAIU people who do not like PvP encounters, but I might be wrong), but at least for me carebears in Dom are the carebears of Diplomacy and not the MMO carebears
