about 90% of fisherman are complete idiots. They gut hook fish, they rip swallowed lures out of fish, they dont know how to handle a fish and hurt it really badly. It is really bad to fight a fish for a long time too because lactic acid can build up and they can not get rid of it like humans and it will poison them. Lactic acid is what causes leg cramps from anaebolic processes in the muscle.
I guess the point is...you might as well keep fish if you are going to do stuff like that. Littering happens when you are fishing, something like a bass rips your plastic lure off, but intentionally leaving crap around pisses me off too. So Peta has a good message on those issues, but they are going about it the wrong way.