This afternoon I flew from the Greater Rochester International Airport. This is one of the smallest airports I've flown out of in ages. However, it did have the Millimeter Wave (i.e. Naked) Body Scanners. Instead of walking through the scanner, I decided to opt out. I told the agent of my decision he said "male opt-out" into his walkie talkie, and I was escorted to an area just beyond the body scanner.
The agent explained everything he was doing. He informed me of my right to be screened in private (I politely declined). This included reaching in my collar, feeling just inside my waistband, using the back of his hand around "sensitive areas" (what some have referred to as "crotchal"), and a wipedown of my entire body. It was the most thorough patdown I have ever received.
The process was certainly not as quick as if I had simply walked through the body scanner, but I do not feel it took an unnecessarily long time. The TSA agents were polite and reasonably efficient, given the protocol they were following.
Why did I opt-out? Partially because I wanted to experience it at least once. This particular time was good as I has plenty of time and the airport was not particularly busy. I also believe I will be doing it where I have to because I feel uncomfortable with the thought that TSA agents can look at my naked body. It also remains to be seen how safe these machines are. Considering how often I travel, I'd rather not take chances exposing myself to unnecessary radiation.
It is troubling to me that so many people are walking through the machine like it's normal. This isn't normal. It's not necessary. There are better, less invasive methods for screening passengers.