It is always best to rebuke them and if they decide to do evil it is because of their freewill. There should be protest about it. To sit back and say nothing is just as bad as doing the evil.
Muman, if I signed a condemnation to Hamas for having aimed rockets to Israel ON CHANUKAH.... would it be a good or a bad protest? Surely bad!!!! It would imply that's it's ok to attack on other days!!!!
If I sign a protest to the Pope for possibly condoning that Bishop and keep silent about the fact that Ratzinger believes non Catholics deserve eternal burning and many other intolerant beliefs and teachings, I would be implying that the rest is ok.