The dozen were issued citations for trespassing and let go. Starks says they face a $1,000 fine or 90 days in jail.
Starks says organizers told police beforehand that some would risk arrest.
The Service Employees International Union was protesting what it calls Sodexo's unfair and illegal treatment of workers. Sodexo says the union was spreading misinformation.
A publicist for the "Lethal Weapon" actor declined to comment.