I hate this (not as much as the middle lane hoggers, but almost). The police often patrol in lane one at less than 70mph, perhaps as they're just going along and intending to pull off at the next exit, or even following someone or whatever.
So, if they opt to drive at around 60-65, you suddenly see all the idiots slow down because they are too scared to overtake. I have no concern in overtaking a police car that isn't driving at the speed limit. Indeed, I don't have a problem keeping up with them when they ARE driving at 70mph. I've never been stopped yet*!
I really do wonder what these people think the police would do if they dared overtake! Of course, given how they do indeed pull on to the motorway and go straight for lane two before switching off, I guess I shouldn't wonder at all.
The silly thing is they think they're safer in lane two, when they now have vehicles on both sides of them. Surely they must wonder why they seem to encounter so much road rage, from people flashing and hooting, cutting in front having had to overtake by crossing TWO lanes to pass, or just undertaking and gesturing?
(* for doing that anyway!)