I don't know how to call the lens that I'm proposing, but the idea would be to put together every source which is written by multiple individuals instead of a single entity. Some examples that are not considered discussions would be ask and answer websites (stack overflow, quora), movie reviews (rotten tomatoes I think), product reviews (not sure if is possible to index amazon reviews), place reviews (google reviews). A harder task would be indexing and displaying the comments from hot discussions in websites without contaminating the whole lens.
