Chanting “What’s outrageous? Starbucks wages! What’s appalling? Starbucks stalling! What’s disgusting? Union busting!”, Starbucks workers at stores across the country walked out Thursday. They are on strike against unfair labor practices and the company’s stonewalling at the bargaining table.

The strike started with sixty-five stores in forty cities, and could spread to as many as 550. The union, Starbucks Workers United, said it is prepared to make this the “longest and largest unfair labor practice strike in Starbucks history.” After rounds of practice pickets in October and November, workers voted 92 percent to strike.

The strike started on Starbucks’ big annual promotional “Red Cup Day,” a day many workers dread, Sabina Aguirre, a Columbus, Ohio barista told the Labor Notes Podcast. Starbucks distributes a reusable cup with most drinks as a promotion, leading to long lines. “It’s one of the busiest days for Starbucks all year,” said Aguirre. “It’s so well known to be a day of overwork and frustration on behalf of the employees.”