A practice I've seen is the following:
- Someone (person A) asks an elaborate question
- which doesn't get enough attention
- Person A sets a bounty
- several answers come but person A is always unsatisfied
- the answers are improved (...but person A is always unsatisfied)
- Some person (B or perhaps A') gives a relatively short answer
- Person A' gets the reward.
Interestingly: when you look at the profiles of A and A', it turns out that they exchange bounties..
How can / does Stack Overflow prevent this from happening?