Why have Ugly Mugs volunteers been deemed 'persons at serious risk'?

Stigma and crime against sex workers can extend to organisations that support sex workers. This is the case with Ugly Mugs Ireland. That Ugly Mugs volunteers have given evidence in hundreds of criminal cases against sex offenders over the last decades has increased the risk. Due to this situation as well as serious assaults, threats, stalking, and other incidents, the UK police has deemed Ugly Mugs volunteers to be 'persons at serious risk.' This means some information about Ugly Mugs volunteers is restricted under the relevant legislation.