Affiliate Marketing Secrets

So Spam sucks – yes.
But the only spam I get is Viagra. Are the spammers actually affiliated with Pfizer? Do they get commission for every 1000 e-mails or something?
I get that it’s a bot sending all the emails, but someone sets the bot up. Do those people get a kick back from Pfizer?
If so, isn’t there legislation prohibiting excess solicitation that would take the problem directly to Pfizer?