He has used that very same site in order to access parents and teachers who have diret access to children. he makes money from doing so, with every click.
If he wants to earn a living he should find an alternative methos that is in no way related to children or schools. That would be the only decent thing to do next.
I was an advice and guideance worker in a prison until quite recently. I worked with men with convictions for thi kind of crime and worse. No decent IAG worker would advice him to return to this line of work. Even if he didn't use the site for this purpose initially, working ina way so closely related to children, would be ridiculous and putting temptation in his way. Madness to suggest such a thing IMO.