To me, the blackhat side has always been about driving the leads using slightly deceptive ways. I guess spamming/xrumer tactics do fall under this, and i guess craigslist aswell.
However I myself draw the line at autofill leads, SSM, Even at times iFraming. I don't know why, but to me its just too fraudulent to get involved in. Which is ironic, considering i developed applications to auto fill leads in when binded to warez, but it is fraudulent in my mind.
Just because you think an advertiser is shady, does not give you the right to use fraudulent tactics on them. Just because a grocery store has outrageous prices on items, doesn't give anyone the right to then steal that food. Ontop of that, Fraud then drives up the shaving/BS that goes on with the advertiser because at the end of the day, they need to make a profit. So whereas people think they are being Robin hood by stealing from the big bad advertiser, all they are doing is screwing over the little guys that are trying to do things legit.