Very true, I picked this example as a thing that kids could theoretically be doing right now. You don't have to go very far back at all to get into the really heinous stuff.
There's a big complicating factor in what parents would have actually prevented as a bad influence too, children cheering on at lynchings were accompanied by everyone else in the town cheering at lynchings.
If there was a disconnect between parents tolerance of lynchings and child exposure to lynchings it didn't last very long.
I find it astonishing that this is the limit of "bad". There are people alive today who were at lynchings in the US as children and cheered them on.
Setting cats on fire by comparison was a harmless past time.