While annoying when it happens, this is really nothing new. Several years back Google search results were inundated with parked domains only serving ads and other such useless pages. Google eventually cleaned up their algorithm. Sometimes their ranking system is gamed, other times they may make changes reducing the quality of rankings. I considered switching to a new search engine and before I could find a better one, they fixed the problem. Complain and then give them a chance to improve. It's a well established cycle that works very well for them.