Big Tech testifies: Bezos promises action if investigation reveals misuse of seller data, Zuckerberg defends Instagram acquisition

This is CNBC's live blog of the House Antitrust Subcommittee hearing featuring testimony from Amazon CEO Jeff Bezos, Apple CEO Tim Cook, Facebook CEO Mark Zuckerberg and Google CEO Sundar Pichai.

CEOs of American tech giants testified remotely on Capitol Hill today—Here's what they had to say

For more than five hours, members of the House Antitrust Subcommittee grilled the CEOs of Alphabet, Amazon, Apple and Facebook four of the country's five most valuable companies, with only Microsoft missing on a wide range of matters. The CEOs dialed in through video conference while most of the committee members were present in Congress, where Chairman David Cicilline, D-R.I., repeatedly reminded them to wear masks to prevent the spread of Covid-19.

For a full recap, check out CNBC's live blog of the event below.

And check out some highlights from the hearing at the following links:

While the topic was ostensibly antitrust and anti-competitive behavior, several Republican members of the committee attacked Facebook, especially, for allegedly suppressing conservative voices, despite the fact that as Rep Jamie Raskin, D.-Md., pointed out the most popular posts on the site consistently come from right-leaning outfits such as Ben Shapiro, Franklin Graham, and Breitbart.

Other members of the subcommittee seemed unprepared with details, with notable exceptions like Rep. Pramila Jayapal, D-Wash., who pressed Facebook's Mark Zuckerberg on whether he'd ever threatened to clone a company who he was trying to acquire, and Amazon's Jeff Bezos on how the company uses data from third-party sellers to inform its own product creation.

Overall, Alphabet's Sundar Pichai received the most scrutiny, while Apple's Tim Cook received the least. — Matt Rosoff

A video of the full hearing is available below: