I had a similar idea a little while ago that takes advantage of using the HTML5 Webworker API to run a Javascript Bitcoin mining script to create a Bitcoin bot-

I had a similar idea a little while ago that takes advantage of using the HTML5 Webworker API to run a Javascript Bitcoin mining script to create a Bitcoin bot-net of sorts. It is interesting though, at least this has a button and seems to run differently. Of course I wouldn't advocate doing such a thing beyond proof-of-concept or you could find yourself in trouble if found out.