We’re in the process of rolling Bing and Yandex image search results into our data. At the moment, you will only see a small subset of the available results until we verify the quality of their results. This means that you may now see a lot of new hits on images which have been dormant in your account for a while. Please let us know if you notice a rise in false positives.
This is an important change – not only will these engines increase the chance of getting all possible websites using your image, but it gives us a level of redundancy and means that we can still deliver some results when the parser breaks (i.e. every time Google updates its SERP layout).