I don't think I'm giving my 17 year old any privacy or autonomy with the computer because he's consistently demonstrated he can't be trusted to use it responsibly. I think I'm being a good parent.
Why do you need him to use the computer responsibly?
So he can't be in contact with certain people.
It's good to protect your kids. Sometimes you have to set boundaries and have them respect the rules you set for them. They may be upset with you though so try to explain your reasoning and give him more chance in the future to prove himself.
I want him to be a normal child and not grow at an unhealthy pace, he should do everything I tell him to do.
You should try to be lenient with your child but it is very important to protect him.