San Francisco city employees working at the de Young and Legion of Honor museums are protesting use of their thumbprints in biometric authorization.

Many city workers at San Francisco museums said that they don’t want their thumbprints given to a third-party contractor to be used in clocking and out of work, as it could make their private information more vulnerable to cyber hacking, reported CBS San Francisco.

Unlike a credit card or Social Security number, union members said that they would not be able to get new thumbprints should their information be hacked.

In a letter to San Francisco Mayor Ed Lee and the Board of Supervisors, union members and staff explained that, “a biometric clock is a violation of employees’ rights to personal security and serves to foster a surveillance culture.”

“Furthermore, the letter states that, by forcing city employees to give their fingerprints “under pain of discipline, insubordination and possible termination,” the Fine Arts Museums has violated the San Francisco Administration Code, which states that the city cannot disclose employee’s private information unless specifically authorized to do so,” reported CBS San Francisco.

If the goal is to improve payroll accuracy, museum workers said they would be happy to clock in with a magnetic swipe card or type in their city-issued Disaster Service Worker ID number, reported CBS San Francisco.

In addition, union workers said that questions of identity could also be addressed by reviewing

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