The worst one is probably trying to make it hard for users to stop paying for a service, like cancelling a subscription. That shit should be punishable by literal prison time.
This actually works quite well. I've had no trouble cancelling any subscriptions in the past few years, including the New York Times, which took maybe 3 or 4 clicks from the account screen (IIRC, there was an optional "why are you cancelling?" screen, then they offered a discount, and that was it).
[1] https://leginfo.legislature.ca.gov/faces/billTextClient.xhtm...