Earlier this year engineer Dr Craig Labovitz testified before the US House of Representatives judiciary subcommittee on regulatory reform, commercial and antitrust law. Labovitz is co-founder and chief executive of Deepfield, an outfit that sells software to enable companies to compile detailed analytics on traffic within their computer networks. The hearing was on the proposed merger of Comcast and Time Warner Cable and the impact it was likely to have on competition in the video and broadband market. In the landscape of dysfunctional, viciously partisan US politics, this hearing was the equivalent of rustling in the undergrowth, and yet in the course of his testimony Labovitz said something that laid bare the new realities of our networked world.

“Whereas internet traffic was once broadly distributed across thousands of companies,” he told the subcommittee, “we found that by 2009 half of all internet traffic originated in less than 150 large content and content-distribution companies. By May of 2014, this number had dropped by a factor of five. Today, just 30 companies, including Netflix and Google, contribute on average more than one half of all internet traffic in the United States during prime-time hours.”

To those of us who were accustomed to thinking of the internet as a glorious, distributed, anarchic, many-to-many communication network in which anyone could become a global publisher, corporate gatekeepers had lost their power and peer-to-peer sharing was becoming the liberating norm, Labovitz’s brusque summary comes as a rude shock. Why? Because what he was really saying is that the internet is well on its way to being captured by giant corporations – just as the Columbia law professor Tim Wu speculated it might be in The Master Switch, his magisterial history of 20th-century communications technologies.

In that book, Wu recounted the history of telephone, movie, radio and TV technologies in the US. All of them had started out as creative, anarchic, open and innovative technologies but over time each had been captured by corporate interests. In some cases (eg the telephone) this happened with the co-operation of the state, but in most cases it happened because visionary entrepreneurs offered consumers propositions that they found irresistible. But the result was always the same: corporate capture of the technology and the medium. And the most insidious thing, Wu wrote, was that this process of closure doesn’t involve any kind of authoritarian takeover. It comes, not as a bitter pill, but as a “sweet pill, as a tabloid, easy to swallow”. Most of the corporate masters of 20th-century media delivered a consumer product that was better than what went before – which is what consumers went for and what led these industries towards closure.

At the end of his book, Wu posed the 64-trillion-dollar question: would the internet also fall victim to this cycle? For years, many of us thought that it wouldn’t: it was too decentralised, too empowering of ordinary people, too anarchic and creative to succumb to that kind of control.

Labovitz’s testimony suggests that we were wrong. We believed that the internet was, in the words of Elisabeth Murdoch, a “sit-up, not a lean-back” medium. It would supplant the old media ecosystem in which powerful corporations decided what content would be produced and then beamed that content down channels that they controlled to essentially passive consumers. That was the world embodied by the couch potato, a world in which the phrase “user-generated content” was an oxymoron.

What we failed to appreciate was the passivity of most of humanity and its inexhaustible appetite for consumption, entertainment and “infotainment”. The spread of high-speed broadband connections did not liberate human creativity but instead created Couch Potato 2.0, a creature that sees the internet mostly as zillion-channel TV. In that sense, it’s no accident that the corporations which now dominate network traffic are outfits like Google and Netflix, beaming YouTube and movies to you in the comfort of your own settee.

Of course the internet of our (utopian) dreams hasn’t ceased to exist. It’s just that it’s becoming a minority sport. You can still create your own website, or start a blog, become a global publisher – and join the long tail of largely unnoticed content, while stuff from Netflix et al swamps the net. You can still make LOLcat videos and screen them via YouTube, Vine or Vimeo; tweet your views and post your status updates to your heart’s content. But you can only do so courtesy of the giant corporations that own and control the platforms on which this user-generated content appears and which – as Labovitz’s testimony shows – are reconfiguring the network for their purposes rather than ours. Sad, isn’t it? We had our chance, and we blew it.