Honestly, the first question that comes to mind if this is illegal (after thinking "dumb, dumb, dumb!!") -
At the daylong “Halacha Conference for Professionals,” held in Brooklyn on May 15, speakers elaborated on a recent ruling by Rabbi Shalom Elyashiv, one of ultra-Orthodoxy’s foremost authorities on Jewish religious law, or Halacha. Elyashiv recently decreed that Jews with reasonable suspicions that a case of sexual abuse has occurred are permitted to go to secular law enforcement authorities, notwithstanding traditional religious prohibitions against mesirah, or informing on fellow Jews.
But at a panel discussion titled “Molestation Issues and Reporting: Current Halachic Thinking,” the panel’s leader, Rabbi Shlomo Gottesman, cautioned that Elyashiv never explained what constitutes “reasonable suspicion.” To establish this, Gottesman said, a person should consult a rabbi “who has experience in these issues” before going to secular authorities.
“If [the rabbi] thinks reasonable suspicion has been met, then you would be allowed to overcome mesirah and report,” said Gottesman, a board member of Torah Umesorah, the National Society for Hebrew Day Schools.
Rabbi David Zwiebel, Agudah’s executive vice president, told the conference that even mandated reporters — teachers, social workers and people in certain other professions who are required by law to promptly report any suspected cases of sexual abuse — should consult a rabbi before going to the police.
“If somebody just comes and makes a claim, that’s not a sufficient basis to invoke the tikkun olam [benefit to society] reason for overriding the general prohibition against mesirah,” Zwiebel elaborated in a telephone interview with the Forward. There must first be “some circumstantial evidence or something that would appear to bolster the claim.”I'd be amazed if the Agudah doesn't get some legal flak over that second statement. Mandated reporters (which often includes Rabbonim, I believe) are mandated reporters, period.
In general, I do believe that people should have at least some circumstantial evidence before making a claim - it's all too common to have false accusations - but to always consult with a Rav first seems unwise, particularly in light of past history.