That Wikipedia article seems to have no bearing on the issue; there's not even any log on a normal user's computer of having or not having clicked a checkbox.

> If they made it impossible for you to prove that you clicked a checkbox or not, then, logically, the burden of proof is on THEM

Even in Europe the only "proof" that's required to companies is a log or database entry (both easily manipulated); if a user strongly disputed to have done it and sued the company for that, maybe you'd able to obtain some investigation on their systems.