Workers in about 10 to 15 stores across the Los Angeles, Seattle and Chicago areas kicked off the strike, which spread to a similar number of stores in three additional metropolitan areas each day. By Monday, baristas in more than 50 stores in cities like Boston, Dallas, Denver, New York and Philadelphia did not report for work.

In what the union has dubbed "The Strike Before Christmas," more than 5,000 workers are walking out of 300-plus Starbucks locations nationwide Tuesday.

A five-day strike by Starbucks baristas had closed at least 59 stores as of Monday afternoon, according to the union organizing the workers