Use and proxy and go to http://www.ip2location.com and they will tell you your proxy IP and your own ISP IP. If they can detect your ISP IP so easily, so can Google. So just forget it.
they also use cookies and look at your browser version etc, if it matched too many times bang. Also they have been banning people with poorly converting traffic lately, so if your users arent interested in stuff you could get banned for that.
Interesting question to think about ... for 2 seconds! It's pretty obvious this is a bad business model, questions about "What if..." are just silly. I mean What if I had an ingenious plan to rob a bank, sure it might be a bit more risky than stealing Advertisers money but its the same damn thing! I know you were just asking out of curiosity, but seriously, what kind of response did you expect?
even if u change ur proxy, the cookies remains in ur PC, if u remove cookies every time, even then u can't do this for long, as google will detect that clicks are coming from same city or country, for google its really easy to detect invalid clicks
C'mon really now. Your asking DP users what we think about your fraudlant clicks. Really. They will most likely target fraudulant clicks via the proxy idea eventually. Just find ways to bring in traffic to give a possible boost of interest to your website. From there a few more users will click.