I did a couple of searches for various terms and you had a huge index for the various terms. Surely such an index is only possible by hooking into search result

I did a couple of searches for various terms and you had a huge index for the various terms. Surely such an index is only possible by hooking into search results from another engine, eventually this will lead to some sort of issue? What's really made it difficult for competitors is being able to match Google's index. Bing crawls a lot of pages but is much more picky about what it index? Also can you say where you are pulling the results from the Yandex API, Bing, Yahoo or Google itself?