So fucking annoying. At least they've started to put refresh-buttons next to them - I often have to try 3+ different images before I get one that I'm able to solve.

I can see the need when it comes to preventing brute-force password breaking, but I don't think they are very helpful when it comes to detecting poker bots. If someone can write a winning bot then they can probably send the captcha to a cellphone and have the owner solve it.