Amazon delivery drivers and Starbucks baristas are on strike in a handful of U.S. cities as they seek to exert pressure on the two major companies to recognize them as unionized employees or to meet demands for an inaugural labor contract.

Amazon's leading E-commerce operations also lead the industry in injury rates. Drivers and warehouse clerks are now on strike, demanding safer working conditions.

The Teamsters said the strike at seven facilities is the largest ever against Amazon. But the retailer doesn't anticipated a slowdown to deliveries.