Fire or riot control truck at CADC Ottawa
 

I drove past their yard today and noticed a vehicle the shape of an airport fire truck, but with a few differences. It is painted a textured white (never seen a finish like it at an airport) and has protective mesh screens on all windows (also not common for airport use, but might be as simple as a brush screen). It is also my impression that the water gun on the rooftop is smaller than average for airport use and there is plumbing for small nozzles to spray/clean the windows. I couldn't read the painted out markings on the side of the vehicle but I'm wondering whether it might have been intended for riot control? It isn't listed yet as being for sale but must be coming in the near future if you are curious.
Sorry, no photos as I didn't have a camera with me and also wouldn't want to excite the security folks by getting too close on a day when they have no (known) staff working.

I remember back around 78 when the CF was buying the AVGPs, there was concern that some could be fitted with water cannon and used on our own citizens. The governments response was "we have no water canons". I was in Gagetown at the time, and there was a lineup of trucks fitted with them for field fire fighting.

Times have changed....I think it could go either way: field use or aid to the civil power.