Most of the busts across Canada this past few weeks have specifically referred to asian micros: Toronto, Saskatoon, etc.
I think maybe the incident in Toronto may be why they seem more interested in reporting the other ones. In Toronto, this guy with website, an "agency", etc, was busted with 2 underage girls there. One was 14, the other was 16 but had been working with him since she was 14. This is the sort of thing that gets the news interested in actually reporting what is not really news. That and the fact these are mainly non-residents, working here illegally on tourist visas (working on tourist or student visas is not legal), so you have the "issue" of "trafficking". If they were local, they would not have as many interesting charges, the excitement of deporting the older sps, etc.
For the non-asian micros, there would not have been that "trafficking" angle or probably no under agers, so the TV and newspapers not very interested.
http://cnews.canoe.ca/CNEWS/Crime/2010/04/17/13622676-qmi.html