Last week, Congress questioned leaders of four of the largest tech companies in the world - Amazon, Facebook, Google and Apple - about just how much power they’ve gained over the years. Today, we're revisiting an episode from December about how Amazon's race to be the biggest and fastest is hurting the employees doing the work. Will Evans, reporter with The Center for Investigative Reporting You can read Will's full Behind the Smiles investigation here. And to share your Amazon injury records with him click here.