Several lawsuits filed against McDonald's on behalf of workers this week say the fast-food chain engages in a variety of practices to avoid paying employees what they're owed.
The suits in California, Michigan and New York against McDonald's and its franchisees come amid growing attention on the country's widening wealth gap and the pay practices in the fast-food industry.
While the practices outlined in the suit are prevalent across low-wage sectors, lawyers said they targeted McDonald's because it's an industry leader.
Taken together, the suits seeking class action status could affect roughly 30,000 workers, lawyers said in a conference call arranged by organisers of the recent fast-food protests. The suits seek back pay and other damages, although specific amounts weren't named.
President Barack Obama, Democratic lawmakers and labour organisers meanwhile have been pushing to raise the federal minimum wage of US$7.25 ($8.50) an hour, which translates to about US$15,000 a year for full-time work.
The suits were announced on the same day Obama was expected to call for stricter rules on overtime pay.
McDonald's, based in Oak Brook, Illinois, said in a statement that it is investigating the allegations and will take any necessary actions.
"McDonald's and our independent owner-operators share a concern and commitment to the well-being and fair treatment of all people who work in McDonald's restaurants," the company said.
The lawsuits detail a variety of violations, including the use of software that monitors the ratio of labour costs as a percentage of revenue.
When that ratio climbs above a target, attorneys say workers are forced to wait around before they can clock in.
In Michigan, lawyers said workers have to pay for their own uniforms, which is a violation of labour rules.
The six lawsuits and one amended lawsuit announced on Thursday include both franchise-owned and company-owned restaurants.
McDonald's is named in all the suits, however, because lawyers say the company exerts control over staffing at all its locations.
"There are a number of ways the two seem to work together," said Joe Sellers, one of the attorneys representing workers, in reference to the relationship between the company and its franchisees.
The vast majority of the more than 14,000 McDonald's restaurants in the US are owned by franchisees.
Workers named in the suits were referred to attorneys by the group behind the recent fast-food protests that have captured national media attention.
The Service Employees International Union has been providing financial and organisational support to the push.
A representative for BerlinRosen, the public relations agency coordinating media efforts for both the fast-food protests and the lawsuits, said the timing of the announcement on the same day as Obama's overtime proposals was coincidental.
One of the suits was filed in New York, two were filed in Michigan and three were filed in California. An amendment to an existing lawsuit in California was expected to be filed on Thursday.