Revenge porn is terrible, but I don't think that's relevant here. Can you think of a plausible scenario where a backscatter machine's data could be used against someone? They didn't save your face; I don't know what someone would look at. And that's if the machines actually saved any data, which was not supposed to happen.
I created fake nudes in high school about 20 years ago... It's always been on the table for an artist to fake them, the only difference in that and deep nudes are that a computer does them. Why is it just now bothering people? Because of the buzz word of deepnude?
In addition to the fact that a computer can create a photograph that is exceedingly realistic with exceedingly little effort, releasing nude photographs of anyone without their consent—fake or not—is a terrible thing to do to another person.
Your youth makes your actions forgivable, but not acceptable.
So what if they see me naked? I don't care. There's nothing harmful that can come from that information.