I think it's wrong of course to monitor adult children like this under any circumstances. The only thing I'd add though is I'd guess many of the kids expect their parents will still pay for their university, car, etc. There is a "their's no such thing as a free lunch" lesson embedded somewhere. It's super shitty of the parents and no doubt destroying their relationship with the kids and probably creating all sorts of emotional problems for them. But the kids (who are adults) could also choose to stop being dependent on their parents if they prioritize independence.