@Dimitar27 In the US and Canada, when someone has been released from prison for serving time as a sex offender, the police have to alert the community where this person settles to live. If it's a pedophile, they'll be forbidden to be within a certain distance of schools, playgrounds, public swimming pools, and other places where children are commonly present. If they are caught violating this, they'll go back to prison, whether they were actually doing anything or not, as they will be breaking the terms of their parole.
You are correct in that these kinds of people live among us everywhere, and the fact is, most are never caught, or only years later, when someone who was abused by them speaks up.
@Linda1091 Yours is a really good question. I don't know the legalities of that, but if a were a parent, or a single woman, I would certainly want to be made aware- it wouldn't lead me not to book, as I know there are sex offenders everywhere who haven't been identified or brought to justice, but if I knew that the host knew, and didn't impart that info, I'd be upset. It would alert me not to walk that way and to avoid that person ifIsaw hemoutin the neighborhood. Whether it's something to mention in your listing, or to only mention to guests who fall into a vulnerable demographic, I don't know.