(CNN) – Twitter users are rightly aghast that the company on Sunday banned a user for openly criticizing NBC’s coverage of the Olympics. After Guy Adams, a British newspaper reporter for The Independent, posted negative comments about NBC’s tape-delayed Olympics coverage (including one executive’s work e-mail for viewers to make complaints), Twitter alerted its business partner – NBC – and showed the network how to file a complaint capable of shutting down the offending user.

Both Twitter and NBC apologized Tuesday, and Twitter restored Adams’ account.

Yes, the Twitterverse should be appalled, but we should not be surprised.

First off, Twitter is a private, for-profit company. Having provided a free service to millions of Internet users for years, the company is attempting to placate and even pay back investors who have been awaiting returns on millions of venture dollars. This means becoming more restrictive, more top-down and more corporate.

Last month, in an effort to raise advertising revenue, the company announced it was closing its API (application program interface) to third-party apps – meaning people and companies can no longer make applications that stream Twitter data. This makes it harder to see Tweets from places other than Twitter’s own website. It’s an entirely less open service this way, but it also gives Twitter exclusive control over how and where people access its content – and advertisements.

And now, as if to prove that it’s more of a corporate player than a tool for corporate critique and other radical activity, Twitter has given its biggest partners a primer in how to ban users that offend them: Simply ask us.

So is the Net suddenly less free and open? No. The Net – at least as a technology – is just as free as it was before. This is simply what happens when we rely on a highly centralized and privately owned tool for a capability that might best be accomplished through a more distributed technology.

The Net might be a big decentralized network, but Twitter is a single, centralized node on that network. Our tweets don’t self-replicate and spread; they go to Twitter, which then essentially broadcasts them to our followers. This is an efficient system, for sure, but it is also highly controllable. The extent to which our messages proliferate depends entirely on the kindness of Twitter, a company that has priorities other than us.

The alternative would be to sidestep Twitter altogether, and re-create its functionality through less restrictive, distributed tools. We could use the messaging equivalent of Napster or Tor – the peer-to-peer networks that let people share music and movies with each other. Instead of downloading files from a central server, people get bits and pieces of files from one another.

Likewise, e-mail travels sideways from server to server, in bits and pieces, with no truly central administrator motivated to ban a particular user for what he’s writing.

We may not like Twitter for what it’s doing, but it’s not up to a multimillion-dollar corporation to act against its own short-term financial interests in favor of freedom of our speech.

It is, however, up to those of us who want a free and open Internet to make the effort to understand how our technologies work and who controls them. Only then will we be capable of exploring alternatives to centralized corporate software, and of building and supporting them.