For nearly 20 years, millions of bare feet have marched through security checkpoints at airports around the country, a motley parade of hairy and Roman toes, calloused soles and cracked heels, nails black from marathons or chipped red from faded manicures. These feet are best enjoyed in private. Yet since 2006, they have been on stark display.

A Massachusetts law enforcement and homeland security consultant who helped draft some of the first rules requiring passengers to remove their shoes at airport security checkpoints says the decision to end the policy raises concerns.

Most passengers had been required to remove their footwear at checkpoints since 2006, a policy later eased only for members of trusted traveler programs.