Airport Security -- Is the USA the only country that allows opting out of biometric scanning?

TSA is mandated by the US CBPO to allow for alternative screening requests. One is allowed to opt out of the new biometric face scans, even the metal detector / x-ray machines if one feels so inclined. I always opt out of the face scan.

Yesterday I boarded a flight from Boston to Asia. Opting out at the TSA desk was easy (though this is not always the case--it took my GF 15 mins to opt out at JFK because …

airport biometric detector machines metal opt out privacy requests scanning scans security tsa usa