Back in the 70's it was common practice in the Kingdom Halls (at least where I attended) that, when a person was being reproved or disfellowshipped, the specifics of his sin were not made known or announced from the platform. However, at the time the announcement was made, there would be a short talk given about the evils of their specific sin (either just before the announcement or directly after).
So all anyone in the audience had to do was put 2 + 2 together to figure out what the perpetrator had done. The talk itself might not go into specifics either, if a brother was guilty of fornication, the accompanying talk might be about loose conduct or sexual immorality.
So, basically, if a young brother admitted to the elders that he pleasured himself, everyone in the Hall could figure it out and know what he did (plus, there's the benefit of the gossip mill). If a parent gave their child a birthday present, everyone in the congregation usually knew what they did.
BUT, if a brother had sex, in any way with a child, all he had to do would be admit to it and promise that he wouldn't do it again, and nobody in the Hall would be the wiser!!
That's messed up!