While this is something that we have to remain vigilant about (case in point, vigorous opposition to SOPA), I think the cat's much too far out of the bag to actually worry about general-purpose computing itself.
To effectively prohibit any general-purpose computer, the government would effectively have to forbid the sale of transistors and solder.
What Microsoft, Apple or any particular hardware or software company chooses to do might be objectionable and annoying but it can hardly threaten open computing itself: I can always build my own PC and install linux.
The government won't forbid the sale of transistors and solder. They don't have to, for two reasons.
Firstly, nobody can build a computer to the standard of a contemporary desktop out of transistors and solder. It simply can't be done, even if you don't care about its size or power consumption. You can build a little 4-bit computer, but that's no use to you. So they don't have to prevent all unsecured computation, they just have to prevent you doing more than, say, a billion cycles of computation.
Second, even if the bar is much lower than that — say, you can buy all the chips you need, you just can't buy them preassembled into circuit boards — that's already an effective suppression of general purpose computation. Maybe you personally have the skills and the time to build a computer from those pieces, but I and most people don't. So I've been effectively prevented from computation. I won't write programs and post them on the net, and the online programming communities will dwindle to a small bunch of experts.
And once almost nobody builds or uses general-purpose computers, it's much easier for the government to say "We can't think of a legitimate reason you need a computer, therefore, anyone who has one is a terrorist/pirate/communist." QED.
The government can subsidise certain electronics aimed at blocking criminal content. The only thing people can be aware of are less choices as companies exit due to uncompetitive conditions.
In Australia, the mandatory Internet Filter failed. But conspicuously, the government is throwing money at ISPs who voluntarily filter. Now most biggest ISPs are adopting it. I predict when companies adopt NBN to leave the one digit megabit era, they'll have to have "appropriate criminal content filters in place" in order to be eligible (Taking a note from UK's internet censorship).
tl;dr: The government can use capitalism to kill freedom of choice. Slower, silent yet deadly.
Edit: The government could make an Internet User Owns Device Act that dictates that the hardware bought can not be sold with such remote access to removing content on the device. The user has to specifically opt-in for the remote removal service. Essentially, people can own their own devices they bought.
Free-market capitalism is only one several capitalist subtypes, a fringe one at that. Also it's "private ownership of capital or means of production" thus ensuring a few masters rule over many wage slaves.
Yes, of course, but that's irrelevant. Drug prohibition doesn't stop drug use either. But it leads to oppression and a vast amount of misery regardless.
To effectively prohibit any general-purpose computer, the government would effectively have to forbid the sale of transistors and solder.
What Microsoft, Apple or any particular hardware or software company chooses to do might be objectionable and annoying but it can hardly threaten open computing itself: I can always build my own PC and install linux.