Re: Fishing Expeditions & Dreams of FOSS Alternatives to Privacy-Violator Waze
You have to comply if the police ask you to stop. That is not the same thing as them having the power to ask you to do so - it may be (and, in fact, usually is) an unlawful abuse of their power.
The only remedy is to complain about police misbehaviour to the police, though. It doesn't affect any prosecution that may result from the unlawful stop, unlike in the US.