I've seen a number of posts in this area suggesting the use of Adlogger for keeping track of, and protecting Adsense accounts. Certainly is a shame since the program definitely helped keep spam-clicking down and allowed AdSense users to protect their accounts.
It was a good program, but it hasn't been "around" in at least 4 months now.... (at least that's when I stopped using it) Try www.asrep.com I use the premium one and love it.
I have never used a spam clicking protector, but don't get enough clicks to worry about it yet anyways!