What is biometric data and what countries require travellers to give it?

Changes to the rules for entering the United States require photos and fingerprints from many visitors, but it's hardly a new thing

New Department of Homeland Security regulations in the United States will, beginning Dec. 26, require all non-citizens (including Canadians) to be photographed while entering or leaving the country.

The initiative is intended to build a comprehensive biometric data collection aimed at improving identity verification, combatting visa overstays and reducing passport fraud. The regulations note: “The best tool to combat passport fraud is to utilize the digital photos contained in e-passports to biometrically verify that a person who presents a travel document is the true bearer of that document.”

This is hardly the first or most intrusive measure when it com