Hmm. Seems like Facebook should create some front entities and buy cheap exploits on the black market. Of course, perhaps they already do. Smart folks work there.
edit
Actually, now that i think about it, someone in the right situation could probably make a nice living for a few years buying cheap/obscure exploits for lots of companies that provide bug bounties and submitting them. Beer money at least, perhaps tuition.
Seems sort of on the scale of small time drug dealer. Illegal, very risky in the long term, but possible to get away with for a few years if you're cautious.