I've been glued to the Ferguson coverage for the last week. Like many people, I've been wondering how this could be happening in a supposedly democratic, developed nation - and I've been getting all of my news via Twitter. No matter what they try and do, the traditional news media has just been late on this story, in the way that traditional publishers began to seem out of date when blogging picked up steam a decade ago.

I've been watching up-to-the-second updates of a situation that should concern everyone who lives in the US. Meanwhile, conspicuously, the story is virtually nowhere to be found on Facebook.

We're increasingly consuming information in filter bubbles. Much has been said about this over the last few years, but it's harmful: if an idea, or an event, hasn't permeated a social circle, it's less likely to than it ever was. Back in the old days, we'd all crowd around a TV for the evening news, or read a newspaper in the morning. Everyone got the same information. Now we subscribe to individuals and curate our own information streams.

Mostly this is a good thing: it's dangerous for everyone to be getting all their information from a single source. But as circles congeal online, they effectively become the same thing: a unified voice of people who more or less agree with each other. Not only is that democratically dangerous, but for networks like Twitter, there's the possibility of it atrophying the network and impeding growth. Past a certain point, introverted social spheres can't grow any further; it makes sense to add a little something to break the surface tension.

But in the democratic sense, a little more serendipity is also a good thing. I want to discover stories I might not have otherwise seen; ideas I might not otherwise have heard.

If Twitter was just a piece of software running as a service, this would be unthinkable: it's not obeying your subscription preferences! But that's not what it is. With this change, Twitter is cementing itself as a media company, just like the broadcasters of old. In its own way, it's curating an information source for you - one that can continue to scale beyond your friends and networks.