From time to time I run into an issue that I occasionally also read about in ads or forums like this--somehow a providers pictures are used to run an ad that the provider did not authorize.  

I've seen this most often in a case where a known provider's ad pops up in ads in a city she usually does not visit.  If the info looks the same as usual I have called providers a few times .  Response has varied from  "that's not me, someone stole my pic", to "that ad site is known for that, sorry but I can't do anything about it", even an "no there's not any other ad, and I'm not there (in this case this ad was present for MONTHS)".    

Do you try to do anything about the problem when it happens? Is it true that some ad sites do this to you themselves and there's nothing you can do to stop it?  

Seems like there ought to be way some way to make people aware of sites that do this on their own, both providers and hobbyists would want to know that, wouldn't they?

Thanks