comment spam

I've had to take the extraordinary action of banning people because of comment spam. Lately I've been removing links from comments that have nothing to do with the comment. This includes, but is not limited to, links that are styled to look like normal text (i.e., colour, no underlining, etc.) and links that use the period as the linked text. However, there are some users that keep putting the links back in. I can only assume that there's a bot or something putting the links back in because after a few iterations of removal and re-insertion, you'd think that a person would get the point. And since the point was not taken, I've banned them.