I just read an interesting interview with Evan Williams, founder of Twitter (and Blogger) that had a great quote:

In response to a question from the audience about Twitter empowering people to publish and act as journalists, Williams — who founded Blogger and later sold it to Google — said that “lowering the barrier to publishing” has been something he has spent most of his career on, and this is because he believes that “the open exchange of information has a positive effect on the world — it’s not all positive, but net-net it is positive.” With Twitter, he said, “we’ve lowered the barriers to publishing almost as far as they can go,” and that is good because if there are “more voices and more ways to find the truth, then the truth will be available to more people — I think this is what the Internet empowers [but] society has not fully realized what this means.”

I like Fred Wilson's take on this too:

When I started blogging back in 2003, I would tell everyone how awesome it was. A common refrain back then was "not everyone should have a printing press." I didn't agree then and I don't agree now. Everyone should have a printing press and should use it as often as they see fit. Through things like RSS and Twitter's follow model, we can subscribe to the voices we want to hear regularly. And through things like reblog and retweet, the voices we don't subscribe to can get into our readers, dashboards, and timelines.

If I look back at my core investment thesis over the past five years, it is this single idea, that everyone has a voice on the Internet, that is central to it. And as Ev said, society has not fully realized what this means. But it's getting there, quickly.