A couple of months ago, at a rock solid 2,300ft near WOD, I received an unsolicited call from the Farnborough ATCO to tell me "Not above your current level due to Heathrow inbounds above".
There then followed a bit of a jumbled conversation, during which I asked her if that was a request or an instruction as I was confused as to the purpose of the call. She fumbled her response, decided it was "advice" and muttered something about Heathrow inbounds being downwind.
It was all complete and utter nonsense, but doubtless as part of their self promotion, has been chalked up as one of the 3,000.