This is probably good enough for most cases, where ham-fisted cops will pull the plug to seize the computer. But RAM isn't instantly wiped when turned off. The

This is probably good enough for most cases, where ham-fisted cops will pull the plug to seize the computer. But RAM isn't instantly wiped when turned off. The capacitors take some time to discharge, and it is possible to quickly snatch a RAM stick and put it in a device that will preserve its content and allow to read it later on. If the strategy you propose becomes more prevalent, law officiers will adapt.