I saw a piece on the news about this when tattoo removal became available on the NHS. They showed two cases. One was a woman who was forcibly tattooed after being gang-raped. She is not the only victim of this sort of crime.

The other was a man who was coerced into a criminal gang when he was younger and was tattooed to show his allegiance. The only way he could get out of the gang culture was to have the tattoo removed as it marked him out to rival gangs. It also prevented him getting a job.