Led Zeppelin are the rulers of straight up jackery. They stole from way too many people to count.. and its made even worse by the fact that they would use the same exact title or a slightly different one... and the same lyrics and melodies.. cant believe they were the first inductees of the "rock and roll hall of fame" and continue to get a pass for this shit.
http://www.youtube.com/watch?v=tiiY4ciKFQA is a decent rundown of some good examples but there are more.
ps. bert jansch is the shit