All parents? All children? All undesirable activities?
Sorry, this is far too broad of a question and almost impossible to answer as stated.
Speaking for myself: my daughter is eleven and all she is up to that may be considered undesirable, is letting her little white dog lick her in the face far too much.
Anecdotally, I think many parents are clueless about their kids whereabouts, friends and activities. Perhaps by choice, because they don’t know how to deal with such things.
I’ve known more than a few parents who were great when the kids were little, but basically checked out when they became teenagers. They didn’t know how to communicate with or relate to them, so it was just easier to turn a blind eye.