Things that did *not* get invented in 2008 no matter what columnists and bloggers think: -People who share values dating each other -People who agree with each other discussing ideas -People liking it when other people agree with them -People shunning those whose views they find scary
The world has never been this sort of university debating society vision of a liberal idyll where people seek out as many opposing views as possible and then sit listening to them and saying "hm, some good points my man". This has never existed anywhere, in any society, outside of tiny circles.