In fact, the things that would make it difficult to do this are routinely criticized by "open source" partisans as tools for suppressing Linux.

The things that make it difficult to do this are only obstacles to adversaries that don't have access to Intel's secret keys. If you have those, by design you can both bypass secure boot and reflash the BIOS with whatever code you like, and the very same restrictions that stop normal users from doing those things also make it impossible for them to detect that it's happened. The NSA has an entire well-funded division dedicated to helping enable eavesdropping by retrieving information like those keys.

Those security features are genuinely only useful for stopping people from installing Linux and open BIOSes. They can only protect computers from their users, not from the NSA.

Exactly. Lavabit example is 100% clear: one user is enough for three letter agencies to get the court request for all the private keys.

The only way trusted computing secures your computer is if you install a TPM chip with your own certificate and constantly verify that it is active. If it runs software signed by Microsoft or Apple, it's useless against a state agent.

Presuming, of course, that the TPM wasn't backdoored (or even just had keys held in escrow where the NSA could reach them), which would be more or less impossible to verify.

Yeah, I'm sure that 'trusted computing' isn't effectively the Clipper Chip by another name.

Remember one simple fact: with all such schemes, the end user is the one party involved who isn't trusted.

They have to gain access to the machine first to do the reflashing. Closed source systems make this a lot easier.

Apple's software update process allows for remote targeting of individual machines by MAC address, for example.

This is interesting. where is this information taken from?

But is that the point? Maybe the solution is not to try to prevent someone else from manipulating your computer. Maybe the better approach is to give the user full control of her computer, including the BIOS.

For reasons that fall far short of evading intelligence agencies, the user should be able to flash her own BIOS whenever she wants.

Better and more choices in open source BIOS solutions might help in this regard.

In my opinion, it is precisely the notion that the user need never control her BIOS that was used to try to maintain IBM's monopoly on the PC, and later to maintain Microsoft's monopoly on the PC OS. Whatever the motivation might be, I would welcome a renewed focus on making the BIOS open and something that a user can choose, just as she chooses her own bootloader and OS.