The web is the most powerful platform for collective discussion in the history of human civilization. However, the form and content of these conversations are effectively owned by a small number of companies.

The photo sharing service TwitPic shuts down for good on Saturday:

It’s with a heavy heart that I announce again that Twitpic will be shutting down on October 25th. We worked through a handful of potential acquirers and exhausted all potential options. We were almost certain we had found a new home for Twitpic (hence our previous tweet), but agreeable terms could not be met. Normally we wouldn’t announce something like that prematurely but we were hoping to let our users know as soon as possible that Twitpic was living on.

With it goes a vast archive of images uploaded by tens of millions of users over a period of six years, including the water landing of US Airways flight 1549 in the Hudson River, the G20 protests in London, and countless moments in its users' lives. In the days before Twitter had support for built-in photos, Twitpic added a layer of visual immediacy that added value to the platform.

It's just the latest in a series of closures. Companies go out of business all the time; when they do, they take their sites with them. A power user will pour years of their lives into a social networking profile, with photographs, status updates, checkins and other details. One site closure can wipe out millions of years of collective personal history.

By placing our online personas in a few centralized locations, we make them vulnerable to single points of failure. That's only part of the problem.

Each service has made design decisions about what their platform feels like to interact with, and with it, the form of the content that's hosted there. Twitter, of course, is limited to 140 characters. Facebook supports a few common formats like status updates, photos and videos. Foursquare is made up of checkins and reviews. And each one contains a logically separate network of contacts, even though we may be connected to the same people on multiple sites.

We all have multiple personae: the version of us at work, in our family lives, and so on. When we publish content, we usually do it from one of those personae and for an audience of people related to that persona. These divisions between sites force us to think in terms of which site we'll communicate with: are we going to publish this content on Twitter or Facebook? Medium or LinkedIn? The implication is that each social network is its own distinct community of people with its own characteristics.

The reality is that the communities connected to each of our personae probably aren't split across social networking lines. These are artificial barriers, which serve the needs of the service owners more than the needs of the content creator. An audience of people may be individuals with specific interests who may be on a combination of social sites, or no site at all.

By limiting a message to a particular social networking service, rather than to an audience of individuals, we unnecessarily stunt our work.

Compounding the problem, many social networks enforce a "real names" policy, and require that you maintain a single profile that represents you online. This forces us to conflate our personas, so that our work connections, our family connections, our friends and our fandoms all sit on top of each other. The intention may be to make our online profiles into a better reflection of us, but in practice it does the opposite; we hold back what we publish, worrying that, for example, a piece of content for our friends may offend our coworkers.

We see these problems in schools and universities, too. The form and design of learning management systems places tight constraints on learning, by having even more limited content types than consumer social networks. Online spaces for classes are removed once the class is over, denying students the ability to build on this content as they continue their learning journey.

Content on the web is not living up to its full potential.

We designed Known to be a focal point for your content. You control where it's hosted (whether it's on our service or somewhere else); you decide what it looks like; you choose what you post and who can see it.

There's no need to have just one Known site. There aren't any regulations about the name you use, or whether your site is public or private. You can syndicate content to reach your connections across networks, and our intention is to allow people to reach each other person to person, and slowly forget about the divisions between networks.

Being able to host and extend your own profile means that you also get to choose the kinds of content you post there. Very few social platforms iterate on the core content types: posts, status updates, photos, videos, bookmarks, checkins and events. Our fellow Matter portfolio members GoPop do a good job with this, and we hope that over time developers will create new kinds of content. We also hope that they reinvent what the content container looks like: there's no need to limit online content to a reverse-chronological stream. We've built easy-to-extend APIs into the heart of Known, and we're delighted that developers are beginning to use it as a lab.

Because your site is fully under your control, you're not subject to the kinds of shutdowns we've seen from TwitPic, Posterous and others. Even if Known the company goes away (not that we have any intention of going away!), your Known-powered site will be alive and well.

Every independent content creator deserves to own what they publish, and to reach their community directly. That's our mission, whether you're an educator or an artist; a developer or a demagogue. We're building a new kind of platform, and we hope you'll join us on this journey.

This post was also published on LinkedIn and Medium.