Municipal police as a locus for PPP’s?

While reading a recent issue of l’Aut’ Journal, I came accross a story claiming that the Montréal municipal police offers privately some of its services (e.g. bodyguards). Well, a rapid visit on the website of the municipal police verified that claim. In fact, there is a whole brochure on the site which details all the services that can be privately purchased from the municipal police. Now I may sound entirely naive and oblivious of some widely known facts of existence, but I had thought that beyond big events which require the presence of policemen to insure security, all that the municipal service did was within the public realm… It might be interesting to know what proportion of its activities are in fact private and where do the funds thus amassed end up… And is such a practice widespread?