While I've managed to avoid the body scanners so far, my luck ran out this morning at BOS, when I got an "SSSS" BP, apparently for buying a one-way ticket.
When I reached the machine, I politely told the TSO I would opt for the pat-down instead. He yelled over to another TSO and they concluded that there is no "opt-out" allowed with an "SSSS" BP. (Perhaps I should have argued further, but I went through the scanner.) Along with the scanner came the full "enhanced" pat-down, complete with crotch check:
Then off to have all of my possessions checked for bomb residue. The TSOs were reasonably polite throughout the process.
I have searched this forum and couldn't find any reference to the SSSS/body scanner combination (sorry if I missed the thread). In addition, I've searched the TSA site and elsewhere and have found no evidence that the body scanner is mandatory with an "SSSS" boarding pass. Do others have experience with this, or relevant information? I'd like to be better informed in case this happens again, and if the TSOs were incorrect, I intend to file a complaint with the TSA.