In some countries, including the US, it is not permitted to wear a piece in jail. If the prison guards realise you're wearing one, you have to check it in. I had a client of mine (I am a lawyer) made to surrender his unit while in prison. It was a nice-looking unit - I wasn't aware he was wearing anything - and it wasn't picked up initially, but of course he had no glue or tape with him when he was arrested. After a few days it was coming unstable and he asked for permission to bring some adhesives in, and that is when they confiscated it. It caused him a lot of grief. He was a good-looking guy, and very sensitive about his hairloss. I think he had kept the piece under the radar till that point.

Moral: if you can't do the time (bald) don't do the crime, (and don't even get suspected of it!)