The Winnipeg stings had nothing to do with federal law, its a local by-law infringement issue. If you advertise as an escort, you need an escort license (very expensive here for an indy, less so for an agency girl). So, the ladies are now service providers, and no longer chargable under the by-law. Haven't heard of any sting activity lately.
Prostitution is legan, but living off the avails, keeping of a common bawdy house and solicitation in a public place are not. Pimps, incalls, streetwalkers are all illegal, so there are still a lot of ways to "trap" a working girl...