'They drive us to the bone' -Starbucks workers strike

STORY: The walkout comes on the one day each year that Starbucks gives away reusable, red, holiday-themed cups to customers with coffee purchases. In the past, the promotion has driven up traffic, resulting in long lines and stores quickly running out of the cups.

The workers say they are underpaid and don't have consistent schedules. They are also protesting firings, store closures and other actions they say are illegal retaliation by Starbucks against them for unionizing.

Starbucks has nearly 9,000 corporate-owned U.S. locations.

Starbucks has said it respects employees' right to organize, that store closings were due to safety concerns and that fired employees violated company policies. The company and union have accused each other of stalling bargaining.