I mostly agree, with one caveat. Yes, most pictures of me on Facebook are from other people. And, yes, any hypothetical pictures that I wouldn't have wanted made public to the whole world would definitely have been posted by a friend ;)
On the other hand, some causes are worth dying for, and some brave souls can take being beat to death by xkcd's $5 wrench - especially when they have even a modicum of hope that not giving up whatever secrets were desired meant that the 4096 bit encrypted hard drive, with whatever links to whatever other people they cared about, would be out of reach of wrench-wielding thugs.
And sometimes you just need to delay the thugs long enough that your revolution becomes thousands strong, and secrets no longer matter.