The account details of 250,000 people who use the website Hookers.nl, used by people who visit prostitutes to compare experiences, have been hacked via a software leak, broadcaster NOS said on Thursday.

The broadcaster said it had verified information that the hacker has put the information, which includes email addresses, up for sale for $300. Although users passwords are protected, email addresses are easily read and many people have used their real name, NOS said.

The website has confirmed that the information has been leaked and contacted all users, NOS said. The site is also used by prostitutes and escorts.

According to Dutch tech website Tweakers.nl, the information was stolen via a leak in vBulletin software, which was identified two weeks ago. The website had not installed patches meant to close the leak, Tweakers said.