Another article about the effects of click fraud on search engine revenue and the Internet advertising industry in particular. It contains a link to a Slashdot thread on fraud. It's an old thread that I missed, which is just as well, because just about everything that was discussed is something I've already considered. (Plus, it raised my blood pressure just reading it.) If you want to get an idea of how I (unfortunately) spent too much of my time over the last few years at AV, read the thread. It's funny -- for most of the suggestions that were posted, I can recall having almost the exact same discussion and reaching the same conclusions.