It occurs to me that someone can continually offer bounty without having to ever actually pay up effectively getting you to work for nothing. Any ideas on what to do about that?
There is no point in doing that...unless you are a really really bad person.
Once you offer a bounty you automatically lose the points offered as bounty.
Even if don't award the points to someone they are still subtracted from your "bank account".
As you can see here:
All bounties are paid for up front and non-refundable under any circumstances.
So I see no gain from teasing someone with a bounty. Who has done that?