Alright, I'm going to put my two cents in here (if no one minds of course)...
If i remember correctly, the show mentioned the Ridge Raiders were a bandit group of Ridge Runners who would give h*** to people like Boss Hogg - wealthy, crooked politicians. Raiders referred to the Raids they did. It was a cross between Ridge Runner and Raiders, with Raiders being used in a term akin to Robin Hood. It wasn't quite explained too well just a little... well, it was more touched on without any real explaining, so you had to infer it from a lot of the incidents that occurred during the episodes.