In response to a flood of comment spam, mostly trying to advertise online poker or sell poker-related garbage, I’ve implemented a comment-password system. Basically you just have to read the instructions and enter the very obvious password into a particular field for your comment to be accepted. There’s no secret to this; it should be trivial for a human to make the adjustment, but the process is just different enough to foil (the current generation) of programs the spammers use to waste other people’s resources instead of paying for their own advertising like honest businesspeople would.