I suppose the difference for me is I've not seen any examples of Child sexual abuse online. Its obviously a bad thing, so steps taken to prevent that directly are a good thing. When you start restricting everyone, in order to stop that harm, then you need to start quantifying risks.
This isn't arresting murderers, this is restricting the sale of rope that murderers might use on their victims. or to get more specific. this isn't banning clubs where murderers can get together. this is imposing checks on all clubs to make sure there aren't any murderers in them.
If it reasonable for the boy scouts to do checks on their members to make sure that a few of them aren't planning a murder? should the boy scouts be responsible if a few boys do go and murder someone? a murder that was planned in the scout hut?
This is restricting the sale of "how to murder people" handbooks, even at garage sales. Therefore every garage sale proprietor is burdened to make sure they aren't selling a handbook explaining how to murder people, even if they got a load of miscellaneous items from an anonymous person.
This isn't arresting murderers, this is restricting the sale of rope that murderers might use on their victims. or to get more specific. this isn't banning clubs where murderers can get together. this is imposing checks on all clubs to make sure there aren't any murderers in them.
If it reasonable for the boy scouts to do checks on their members to make sure that a few of them aren't planning a murder? should the boy scouts be responsible if a few boys do go and murder someone? a murder that was planned in the scout hut?