Also, the more content you add to a website the more frequent bot visits you get. More threads and more posts means more content for them to crawl. They're hungry little critters and will consume all the content you make available to them.
"Of all tyrannies, a tyranny exercised for the good of its victims may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end, for they do so with the approval of their own conscience." -- C. S. Lewis