Regarding the latest stupid law suggestion @Flick just linked to, here's an idea.
ALL legislative bodies should have attached to them a team of devil's advocates, whose sole job would be to find and publicise ways in which any proposed law could go wrong, lead to overreach or be misused.
They should be thoroughly apolitical and consist of cantankerous, yet rigorous contrarians who don't give a damn and delight in tearing apart stupid ideas. Bonus points if they could do it in an entertaining manner.
It wouldn't stop all stupid ideas from becoming laws, but it would at the very least guarantee someone with an official position would always be there to naysay.