The Radiocommunications Agency (OK, Ofcom) is rolling out quite a lot of remote spectrum monitoring and DF'ing, although it doesn't say too much about it.
There's a bit here.
However, I understand that the agency (oko) has certain, er, issues when it comes to monitoring some of that funky new 5GHz WLAN stuff - ie, it can't, because none of its bits go that far up.
R