HESOYAM on Gehennas is a pretty well known guild with their cancerousness. It's like their hiring policy is that you must be an annoying twat willing to grief fellow Alliance whenever given the chance. Had multiple super bad experiences with them, while almost no bad experiences with a whole guild otherwise, so neither I or anyone I knows takes them in groups, etc. There is no other guild that I'd even really notice in terms of culture, good or bad.
Their members have also been dropping N bombs in chat in different ways, bypassing the chat filter, so you get the idea. It's just bunch of edgy and angsty fucks.