I think it was Bakker, who in a blog post, was discussing how communicating via the Internet, we really lose a great deal of sensory information we would have and use in person. Things like visual and auditory cues and clues, that facilitate our understanding of what the other person is saying and trying to say. So, at least in that sense, minimally, the Internet is actually a very big filter, because now we can communicate, easily, but without any of those "extra" methods of informational exchange. This is both a blessing and a curse, really. It's pretty known, generally, that people will write, or type, things they'd never actually say out loud, let alone, to another person. So, in that case, the Internet can be something that diminishes the level of discourse.
By the same token though, it can elevate as well. Likely, none of us would have time to discuss everything we do here in person. So, there is an element of connection that can elevate discourse. The key is that you will get out what you put in. If all you put in is negative, projected ideas, that is all you are going to get out. So, in reality, the Internet is probably the biggest and grandest psychological mirror we've ever, technologically, made.