John H. Gass’ driver’s license was erroneously revoked after an anti-terrorism computerized facial recognition system that scans a database of millions of state driver’s license images picked his as a possible fraud.

It turned out Gass was flagged because he looks like another driver. His driving privileges were returned but, he alleges in a lawsuit, only after 10 days of bureaucratic wrangling to prove his identity.

At least 34 states are using such systems. They can reduce fraud by 80 percent, said Lisa Cradit, a spokeswoman for L-1 Identity Solutions, a maker of the software.