The MMW scanners are used in Russia. I get the impression from talking with someone I know who traveled there that opting out is not possible (If someone has information to the contrary, please let me know). A poster on this forum reported his wife encountering MMW scanners in Ukraine and that opting out was not an option. Another poster reported encountering a BKSX scanner in Kazakhstan; the poster reported that it was unclear whether opting out was possible and assumed that it was not.