I hope they just focus that hatred in a positive way and vote in their countries to influence how their own governments deal with the US. And don't take it out on individual American citizens. Voting would have the best effect... if other country's governments would somehow penalize the US for the actions which they don't approve of by whatever legal means at the disposal of the international community (i.e. trade and travel embargos, etc.) then, if enough countries join in, US policy can be effected, and US voters influenced, randomly attacking US citizens however, will have the exactly opposite effect that might be desired. I don't agree with all my governments policies, and I vote my conscience on those matters. That is all I or any other person can do, no matter what country you are in (provided it is a democratic one of course).
James Murphy's solution (right above this) is interesting, but I doubt it would work outside of theory, look at the failure of the UN to keep us from acting against the world's best interests. Joey Vera and Mike Patton kept it to the point.
Andy Sneap's reply was the funniest. Jack White, you fucking suck!