If none of those people can actually see you, then why do you object? Personally, I would rather be seen than touched, which feels much more invasive. Even if someone sees the scan, it's not like they are looking at porn and getting a thrill out of it. They get sick of seeing body parts very quickly and just do it because it's a detail of their job, just like a doctor. But what makes you think passengers are the least likely to bring explosives aboard? That's one heck of a big assumption. And the other employees you mention do get scanned, when they arrive for work. But, all that aside, yes such precautions are necessary, even if uncomfortable. As someone else mentioned, once something horrible happens, people run around crying, "Why didn't they do something?" Well, they're doing something. If you don't like it, don't fly.