Most of my pins are ones I've loaded onto Pinterest using the pin marklet. When I first started I actually uploaded some of my own photos too. The pins suggested for me by Pinterest are actually better than a lot of pins I see on the community "Street Style" type boards I subscribe to (now only one).
But the only way I can figure out how to shut down the suggested pins is to report them. I'm thinking it's easier to just ignore them. I don't get that many of them anyway.
Many of my pins are from retailer sites, Shopbop, Barneys. And no one re-pins those. However they are useful to me for outfit creation. People seem to respond much more to real street style photography than catalog-style photography when it comes to pins.