Common about raising autistic adult?

Hi, I’m completely new here on NAS and I’m curious and hoping I can get an answer to my question.

My question is this: is it normal for a parent to put their adult autistic child in front of the TV or computer almost 24/7 just to protect themselves from their own child because the child might damage the house or harm other family members?

I’m having a hard time accepting this, because the autistic person is causing a lot of harm online, and the parent wants me — as someone who has been affected — to “grow a thicker skin.” The parent is aware that their child is harming others, especially many children, and that he has certain urges that don’t work in real life.