Amazon's Jeff Bezos, Apple's Tim Cook, Facebook's Mark Zuckerberg and Google's Sundar Pichai testified via video conference before a US Congress antitrust committee Wednesday. It is the first time all four have appeared together for a joint hearing.

Lawmakers accused the companies of stifling competition and abusing their market dominance at the expense of consumers and innovation. 

Critics of tech giants say tougher regulations and new laws are needed for oversight of tech companies and consumer protection.

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Facebook's Instagram grab

The executives maintained their companies offer essential services to consumers and encourage competition and presented data to lawmakers showing how competitive their respective markets are.

However, they sometimes struggled to answer direct questions about their business practices. 

Zuckerberg was grilled on Facebook's purchase of rival social media platform Instagram. 

Jerrold Nadler, a Democrat leading the House Judiciary Committee, told Zuckerberg that documents obtained from Facebook "tell a very disturbing story" of the company's Instagram acquisition, saying the CEO called the photo messaging service a threat that could "meaningfully hurt" Facebook. 

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Amazon stealing data?

Amazon was accused of hurting small retailers by being both a retailer and a marketplace. The company was accused of taking data from vendors on its platform and using it to create Amazon labeled products. 

In his first testimony before Congress, Amazon's Bezos said that while there is a policy against using seller data to aid private label business, he "couldn't guarantee" that the policy hadn't been violated. 

Apple's App Store was said to force developers to use its payment system in order to have their apps on Apple devices. 

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Google's Pichai was questioned about ethical issues surrounding presenting third party data as being owned by Google and manipulating search engine results to the company's own advantage.

Pichai said that Google's search engine only blocks out websites to "comply with law," and otherwise search results are run by algorithms.

'Too much power'

David Cicilline, the chairman of the House antitrust subcommittee, said the tech giants "have too much power."  

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"Whether it's through self-preferencing, predatory pricing, or requiring users to buy additional products, the dominant platforms have wielded their power in destructive, harmful ways in order to expand," Cicilline said.

The Democrat Congressman added that the COVID-19 pandemic will likely mean the companies will "emerge stronger and more powerful than ever before" as companies and business shift more operations online. 

Current US antitrust laws make it difficult to crack down on companies for being too large or dominant without proving harm to consumers or abuse of market power. 

The US Congress can rewrite antitrust laws, and the congressional committee would play a key role in drawing up a blueprint for new antitrust laws in the digital age. However, this would require a fundamental change in century-old US competition rules. 

wmr/rt (AFP, AP, dpa)