It's always that cycle. up security, someone beats it, endless process. the more 'challenging' it is, the more people want to beat such challenge...if there was never such thing as spam controls, eventually spammers would get bored and move onto something else.
They get attention from news media, being banned, etc. same thing when you click an 'unsubscribe' link in one of their emails. to them it's feedback, and, even while negative, like comercial advertising, ANY publicity, even negative publicity, is good publicity.
ignore them, they'll go away. if only it were that easy.