The top US tech bosses faced a grilling from Congress – taking shots from one side over alleged anti-competitive behaviour and from the other over supposed bias on their platforms.

The hearing in Washington saw Facebook’s Mark Zuckerberg, Google owner Alphabet’s Sundar Pichai, Amazon’s Jeff Bezos, and Apple’s Tim Cook – who all appeared via video conferencing, as has become the norm for many in these trying times – face a barrage of questions from members of the House Judiciary’s antitrust subcommittee.

The subcommittee has been investigating the four companies for over a year, taking into account over a million documents and hundreds of hours of interviews when looking into just how dominant the platforms are in the online world.

The Democrats on the panel focused on the issue of competition. In particular, they dug into Facebook’s purchase of Instagram and pushed Zuckerberg to admit his company copies features from competitors, questioned Google about how it steers traffic and accused it of stealing reviews from Yelp, probed Amazon over whether the company has used data from third-party sellers to help make sales decisions, and surfaced concerns about the amount of power Apple has over the rules on its App Store.

Zuckerberg faced several questions about Facebook’s purchase of Instagram in 2012 and whether the acquisition was made because Facebook viewed the app as a threat. To support this line of questioning, the subcommittee referenced an email it had obtained where Zuckerberg called Instagram a threat, prior to making the acquisition.

The Facebook boss, of course, defended the purchase of Instagram, arguing that Instagram was just a small photo-sharing app at the time and Facebook helped it build as it began to grow rapidly.

In response to questions around copying the features of competitors, Zuckerberg said that Facebook has “certainly adapted features that other have led in”, but he was unable to put a number on how many companies it had copied.

Pichai faced strong accusations of theft – with Representative David Cicilline of Rhode Island, a Democrat, asking “why does Google steal content from honest businesses?”. This question formed part of allegations that Google stole reviews from Yelp and threatened to block the review site from search results if it made a complaint about that.

In response, Pichai was reluctant to argue against the claims without knowing the full details of what his company is being accused of. He did, however, say that Google conducts itself “to the highest of standards”.

For Bezos and Amazon, he was asked about his company’s use of third-party seller data. The use of this data had been denied by an Amazon executive under oath in a previous hearing but was contradicted by a later report. The Amazon boss responded by saying the company had a policy against the use of third-party seller data and that action would be taken against anybody found to be violating that policy.

Bezos was also asked whether Amazon has been favouring its own products when prioritising shipments during the ongoing coronavirus pandemic.

The final member of the infamous foursome, Cook, faced questions over concerns that App Store review process rules were not available to app developers and over the alleged removal of competitor apps from its App Store.

Representative Hank Johnson of Georgia, a Democrat, said, “The rules are made up as you go and subject to change – and Apple expects developers to go along with the changes or leave the App Store. That’s an enormous amount of power.”

Cook defended his company, saying that the App Store cannot be called a monopoly because it doesn’t charge 84 per cent of the apps anything to be listed there.

From the Republican side of the house, much of the discussion was steered away from competition toward China and their belief that the platforms are biased against conservative views.

Zuckerberg and Pichai had to deal with the barrage of accusations over their alleged anti-conservatism.

Zuckerberg was asked about whether content moderators were biased toward conservative content. The Facebook boss, as expected, said that all content moderators were trained to be neutral. Of course, when accusing of bias on the platform, Representative Jim Jordan of Ohio failed to mention the reach that conservative publications and figures enjoy on platforms like Facebook, despite a supposed bias against them.

Pichai faced a more direct question of whether Google would take efforts to help Democrat presidential nominee Joe Biden. To which, he responded, “we support both campaigns. We approach our work in a non-partisan fashion.”

On the back of the hearing, a detailed report into antitrust allegations against the four tech giants could be released later in the year by the committee. Lawmakers are also looking at the possibility of new antitrust legislation, but that’s a long way off coming to fruition.