It's always been the case that the local councils, that licence for massage (not all do), in the UK plus the police and press, join all of the sites like this. We knew it back in the days, before this site existed, so there's nothing new in it. Reports and comments, from UKP, have been used in closures and prosecutions of shops, down South. Led to Be Healthy being shut down in Glasgow, too.
With flats, it's a police matter and if they wanted to, they could easily bust from gumtree and vivastreet ads., never mind leads from A/W or from reports on here that identify brothels.