I’ve added a simple math question to the comments. I don’t like inconveniencing innocent people to stop the guilty, just in principle, but I was getting really tired of deleting all the spam from my moderation queue. If you can’t figure out the correct answer to the math question, your comment doesn’t even make it into the queue now. But when you fail, it will tell you the correct answer, so it’s really more of a literacy test than a math test. If you’re able to read, you should have no trouble submitting a comment. And if you’re not able to read, well, you should go learn instead of submitting comments here.