Summary: Leaders of four tech giants testified on Capitol Hill Wednesday, with lawmakers grilling them about whether they are too dominant. The CEOs of Amazon, Apple, Facebook and Google appeared by video at a hearing of the House Judiciary Subcommittee on Antitrust, which has been investigating the companies for more than a year over possible unfair practices toward their competition. Amna Nawaz reports. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders
