A WebmasterWorld thread has a publisher who has a friend, who was solicited by someone to prepay/buy his Google AdSense revenues up-front, before he earns the money.
So this guy went to an AdSense publisher and reportedly said, I'll give you $X now, if you give me your AdSense earnings for the next Y months. At least that is how I am understanding it.
Supposedly, it is not that uncommon for AdSense consultants to work with publishers and guarantee certain revenue in exchange for a large piece of that. But to prebuy the revenues seems like hedging.
If I had to guess, this guy is looking to generate a lot of bad traffic to this guys site in the hopes of making a quick buck fast and then moving on to the next site, after the publisher gets banned. I can be wrong, but this seems suspicious.
Forum discussion at WebmasterWorld.