Billionaire bosses to feel the heat over tech giants' massive wealth and power

Extraordinary hearing will see some of the richest men in history called to account for their firms' market dominance

Some of the richest men in history representing the most valuable companies ever created will be grilled by Congress on Wednesday , as US authorities get increasingly serious about whether tech giants Amazon, Apple, Facebook and Alphabet have become too powerful.

Related: Clashes in Portland as Trump's actions light fuse under protests in other cities