Longtime American Airlines pilot Mark Woodall thought nothing of it when he took 16 days of military leave for a routine training with the U.S. Naval Reserve in June 2001. But eight months later, he learned the airline had reduced his 21 annual paid vacation days to 19. The company had counted his military leave as a “leave of absence,” which meant he couldn't accrue vacation time during that period.

Cutting two vacation days may seem innocuous, but a recent DOJ lawsuit suggests otherwise. The Jan. 12 complaint, which could affect more than 100 former and present American Airlines pilots, suggests the company violated their rights under the Uniformed Services Employment and Reemployment Act (USERRA) when it allegedly targeted their employment benefits. This is the first class action lawsuit the government has filed under USERRA, the law protecting employees who take military leave. It's not likely to be its last.

This stepped-up enforcement, coupled with a new set of USERRA regulations, is leaving companies bewildered and vulnerable just as those serving in Iraq and Afghanistan are returning home in droves.