Very fortunately indeed, hardly any males have this brutal surgery, which has a high risk of infection and doesn't produce anything comparable to female genitalia. As I understand, a high proportion of male prisoners who have a trans identity only declare this after they are charged or even imprisoned. Some of them may be sincere, but given that quite a number of them are registered sex offenders, there has to be a suspicion that some of them were trying it on in the hope of getting a cushier option than male prison, ready access to vulnerable women and also putting female prison officers in an uncomfortable position.