For those who drive/intend to drive in France, as from 1st January 2012, it is illegal to have any form of advance warning of any type of offence detection camera
, whether it be a fixed site or area of camera surveillance. Max fine of 1500 Euro.
Detectors of any sort have always been illegal, but now ANY system which gives a location of a camera using existing GPS technology is included ie fixed in-car systems which provide GPS location of speed cameras.
I have not seen details of any proscutions yet, but rest assured the Gendarmes will certainly be checking.