The patent grant puts the burden of proof on the alleged infringer, on the theory that a granted patent has been pre-vetted for all the right criteria. But when I look at patent litigation, it seems (and perhaps this is a selection bias problem) that in most cases, about 90% of the patent claims get immediately thrown out. Doesn't it seem that the presumption that the patent grant is a strong enough process to force the burden of proof onto the infringer is just a social mistake? If the burden of proof shifted to the patent holder, it would totally change patent litigation, while maintaining all the abilities we applaud about the patent system -- the ability of a patent holder to sue an infringer who stole their idea, and get compensated.