Three Walmart workers were arrested this morning after attempting to deliver a petition to the offices of Christopher Williams, an NYC-based member of the mega chain's board of directors and CEO of the investment bank Williams Capital Management Trust.

According to the advocacy group Making Change At Walmart, the petition demanded that "the company publicly commit to provide full-time work with a minimum salary of $25,000, reinstate workers who were fired for striking and agree to stop all retaliation against workers calling for better jobs." The petition reportedly garnered more than 200,000 signatures.

The protest is spanning 15 cities around the country, including San Francisco, where participants plan to gather outside the apartment of Yahoo CEO Marissa Mayer, who was appointed to the company's board of directors in 2012, USA Today reports.

The average annual salary of a Walmart sales associate is just $15,500, according to the group's website, and the average hourly wage is just $8.81.

Wal-Mart spokesperson Brooke Buchanan denied that figure, telling the paper that the company's average for full-time associates is around $12.80.