X-Frame-Options is worth less than you think

JavaScript allows you to exploit human cognitive abilities to a remarkable extent; tools such as window positioning, history.forward() and history.back(), open some scary possibilities that we are completely unprepared to deal with. This proof-of-concept aims to demonstrate this; while it is intentionally crude and makes no real effort to conceal its operation, the transitions can be made seamless and very difficult to perceive. Very accurate click prediction can be achieved by carefully measuring mouse velocity and distance to destination, too.

I discuss these attacks and many other unsolved challenges in web app design in "The Tangled Web". A similar approach poses a problem with many browser UIs; for that, check out this post.