Since Labor is scarce for F2P players, this has encouraged a number of them to take up bot hunting as a sport for fun and profit.
This is clever because it utilizes humans for the computationally difficult task of differentiating bots from regular players. This is a task that humans are quite good at, and are especially good at continuing to identify bots as their behavior changes. Botting, as Justice Potter Stewart said of pornography, is something that "I know it when I see it".
It's also quite meta, in that it makes a mini-game out of removing bots, which is highly appropriate in a game.
Well done, Trion. Let's just hope that this doesn't go to the next stage:
Shortly before the Patrician came to power there was a terrible plague of rats. The city council countered it by offering twenty pence for every rat tail. This did, for a week or two, reduce the number of rats—and then people were suddenly queuing up with tails, the city treasury was being drained, and no one seemed to be doing much work. And there still seemed to be a lot of rats around. Lord Vetinari had listened carefully while the problem was explained, and had solved the thing with one memorable phrase which said a lot about him, about the folly of bounty offers, and about the natural instinct of Ankh-Morporkians in any situation involving money: “Tax the rat farms.”
- Terry Pratchett, Soul Music