Overly strict parents

Okay I've been reading a lot about parents controlling what their kids do after the age of 18 and still living in the parents house. I'm reading things like no dating, not allowed to spend the night at anyone's house, going through their phones and bedrooms. In my opinion this is controlling and abusive behavior. I really don't think this is healthy or normal. My question for you is if you think these parents have a right to do things like this? Do you agree that thi type of behavior is okay?