This is actually quite true. The Internet already exists in a state where it could be dismantled even in pieces. Botnets, or even organized effort, directly against the root DNS servers would already cripple the Internet in every meaningful way. Or DoSing certain important routers/switches in the network.
The point being, in this particular situation, governments can more easily censor, but people wield the WMDs. Self-destruction isn't a particularly good method of fighting, but suppose things began to change, ever so slight, in steps. How long do you suppose it would take for organized parties to cripple a key government network (externally of course, nothing that compromises safety would get enough people behind it)?
There is no off switch, there is not going back. At least not in the United States. They can certainly errode things... have the NSA or FBI pick up server records, suspend domain names of sites that perform 'undesirable' functions... but in the end, a threat to the basic tenet of freedom of speech on the Internet would result in the largest riots we've ever had in human history, most of them digital riots.
I think the US might have figured that out already. They've opened Pandora's Box, there's no keeping society completely in the dark any more. But the rest of the world has almost certainly not, and if the rest of the world forces things to come to a head, it would likely be the most widespread series of counter-governmental actions we've ever experienced in recorded history. You think that all your little drones in Democratic Banana Republic are nice little docile things? Wait until you take away the Internet. It has, in very short order, become one of the things that the masses have unconsciously said "No, this you cannot take away or things get bad".
I don't think people would jump straight to conflict or revolution, but if you gave it time, and things persisted, we'd either have a huge number of governments deposed, or we'd have at least one large-scale war between people who hijack their county's political process to use force on other people who are doing things they don't like.
At this point, the Internet in its "free speech" form has become an unremoveable part of human infrastructure. Its absence would cause major chaos and destabilization of the status quo, and guess what all the people who call the shots want? The status quo.
In the end, so long as they understand even the most basic concepts of cause and effect, I don't believe we'll ever see the entire Internet lose its free speech on large scales. We'll have to fight little brush fires here and there, where such-and-such website gets into a legal battle with the government, but not wholesale authoritarianism. Simply taking away the "right" to the Internet from everyone would be the surest way to insure that the status quo doesn't last very long.