God tells his prophets in the OT that, if they fail to admonish the people for certain things, the prophet is accountable for the sins of the people, too.
Likewise, if a scoundrel is loose in a community, and I know he is such, I am (or can be, depending upon the circuмstances) responsible for the damage he does if I remain silent.
Bottom line: Sometimes speaking IS criminal, sometimes it is silence that is criminal. One must read the situation and make a decision, realizing that not all will likely agree therewith.
Would you wait until your sister returns home from a date to inform her that the man she is going out with tonight is someone you KNOW to be a rapist? Hey, maybe he has changed, right? The law hasn't caught him yet, so can you speak of his known crimes?
This matter is NOT as cut and dry and many would like to believe, nor as simple as the would-be dominators of the world want those they would dominate to believe.
The ѕуηαgσgυє THRIVES on such mind games. To be an informer about a Rabbi's evil deeds with boys and/or girls, is a crime worthy of death. This truly wicked spirit has penetrated the West, and we are dying as a culture because no one will speak of/confront the evil in high places (or low, for that matter).