This marking on the boots of both riot police and faux protesters at the Montebello summit is the trademark of "Vibram", an Italian company that produces rubber outsoles for footwear. They appear on the Matterhorn assault boot pictured left as well on many other makes and models. So the "protesters" and police are not necessarily wearing the same boot.
Update: BeneD has found a few other possibilities for the boot-bottom logo. IMHO, though, the blow up (link from "this marking") shows something roundish, not triangular--more like the Vibram TM.
Update: Here's a shot that shows both cop and protester boots side-by-side. The only thing is, Vibram makes about dozens of different sole-types that then get slapped on different boots. For example, the one in the picture looks most like their 109 Logger or 134AR Technical Lug, which are both fire/police models. So, again, it could be a case of different boots but the same sole.