According to tweeting travelers, many backscatter and millimeter-wave AIT scanning machines at airports are not in use at all, making opting out impossible. We've asked DHS/TSA for comment, but you can help us confirm.
Sounds about right. Fizzle the whole opt-out movement by doing less naked body scans and invasive pat-downs than normal. The fact they did that at all suggests the opt-opt movement had an impact. Or maybe they did it just to speed people along.
Of course, the best way to opt out: not fly in the first place.