[I should mention a curious fact-that the Rambam says the obligation to testify is only if the plaintiff or defendant ask him to come to court when the issue is דיני ממונות- an issue of money. But when it is an issue of דיני נפשות human life, then he must testify whether he is asked to or not. That is what the Kesef Mishna says right there on the Rambam himself--that in issues of human life he has to testify whether asked to or not. The trouble with all this is ספר המצוות מצוות לא תעשה רצ''ז where the Rambam says even in issues of money one must testify if he saw the events whether asked to testify of not because of the verse לא תעמוד על דם רעיך. This looks like a problem since in Mishne Torah the Rambam says in הלכות עדות that one must testify only if asked to.
The Chafetz Chaim made known the problem of slander, but this is emphasized in the religious world mainly to give them a blank check to do their abuses and crime and then when an innocent baal teshuva speaks up he is accused of lashon hara,
People that know that teachers of Torah are fraudsters need to speak up because they know testimony that others need to hear.
The astonishing amount of damage the supposed teachers of Torah do is so out of proportion to the expected normal bell curve that I suspect that Reb Nachman was right that they are demons. [LM vol I ch 12: Torah scholars that are demons etc.] [According to the normal distribution, you would expect some to be good, some to be bad and the vast majority around average. But what you actually find Torah scholars do an astounding amount of evil and damage. The curve it tilted far by far towards evil. Perhaps it is because they are not Torah scholars at all but demons using the Torah to make money? That would seem to have been the Rambam's view.]
It does no good to do like Na Nach to just simply complain about them in general. People need to make known specific events of abuse and to shout it from the rooftops.
Because of this problem I simply avoid the religious world and stay away from them as far as possible.
Is there any correction for this problem? Not that I know of. The Litvak world which is by far the best is also infected. The supposed solutions I tend to believe actually aggravate the problem.
The best thing thus is to learn Torah and Musar on your own and forget about the organizations that claim Torah. Something of the Dark Side has taken control of the religious world.
One thing that lends itself is the occult. Though the Ari and his system is very impressive, still it lends itself to empower these teachers by their claims to secret knowledge. It is just a perfect trap for naive people that want a taste of the supernatural.