I think there was an option not to consent and still make it through security, but the instructions seemed to be purposefully unclear. If they make it unclear, they know that 99.9% of people will not bother to ask questions. They know how stressful airport security is in the first place and how people just want to shut up and make it through the line and not miss their flight, and they use that as an advantage. I consider myself to be more informed and concerned about digital privacy issues than a vast majority of people, just like most of you who will be reading this comment.
Even so, in the moment I gave in and let the stupid thing scan my face. And now my face is somewhere in a server at the Pentagon probably. The social engineering around it made it very hard to figure out whether or not there was any real risk of resisting it or asking questions. I was with my wife and we didn't want to miss our flight.
I applaud the person who in the same situation would have turned around and walked out of the airport and skipped their expensive, non-refundable trip to Europe. But when my big moment came to be a heroic activist for digital privacy rights, I wasn't the same person I am when complaining about Facebook and Google on the internet. Oh well, I guess travel is how we learn about ourselves, right?
And that's exactly why facial recognition is going to become completely ubiquitous without much fuss at all. The risks are too abstract for most people to really care in the moment, even if they know the issue fairly well. Real social movements don't gain momentum until people's lives are directly impacted - and the issues are just too nuanced, and the whole infrastructure of surveillance too byzantine, for people to really want to take action.