FILE - This Thursday, Jan. 3, 2013, file photo shows Google
FILE - This Thursday, Jan. 3, 2013, file photo shows Google's headquarters in Mountain View, Calif. Two bipartisan groups of state attorneys general are launching separate antitrust investigations into Facebook and Google, Friday, Sept. 6, 2019, adding to regulatory scrutiny of two of the world's largest and most ubiquitous tech companies.(AP Photo/Marcio Jose Sanchez, File)
PHOTO: Marcio Jose Sanchez/AP/FILE
Now playing
01:18
Ohio attorney general: Data is the new money
WASHINGTON, DC - JUNE 22: Facebook
WASHINGTON, DC - JUNE 22: Facebook's Chief Operating Officer Sheryl Sandberg speaks with AEI president Arthur C. Brooks during a public conversation on Facebook's work on 'breakthrough innovations that seek to open up the world' at The American Enterprise Institute for Public Policy Research on June 22, 2016 in Washington, DC. (Photo by Allison Shelley/Getty Images)
PHOTO: Allison Shelley/Getty Images North America/Getty Images
Now playing
01:23
Hear Sandberg downplay Facebook's role in the Capitol riots
screengrab US social media
screengrab US social media
PHOTO: Getty Images
Now playing
04:35
Tech companies ban Trump, but not other problematic leaders
PHOTO: Samsung
Now playing
01:53
See Samsung's new Galaxy S21 lineup
PHOTO: CNN
Now playing
02:47
Extremists and conspiracy theorists search for new platforms online
This illustration picture shows the social media website from Parler displayed on a computer screen in Arlington, Virginia on July 2, 2020. - Amid rising turmoil in social media, recently formed social network Parler is gaining with prominent political conservatives who claim their voices are being silenced by Silicon Valley giants. Parler, founded in Nevada in 2018, bills itself as an alternative to "ideological suppression" at other social networks. (Photo by Olivier Douliery/AFP/Getty Images)
This illustration picture shows the social media website from Parler displayed on a computer screen in Arlington, Virginia on July 2, 2020. - Amid rising turmoil in social media, recently formed social network Parler is gaining with prominent political conservatives who claim their voices are being silenced by Silicon Valley giants. Parler, founded in Nevada in 2018, bills itself as an alternative to "ideological suppression" at other social networks. (Photo by Olivier Douliery/AFP/Getty Images)
PHOTO: Olivier Douliery/AFP/Getty Images
Now playing
03:49
Parler sues Amazon in response to being deplatformed
PHOTO: Twitter
Now playing
02:39
Twitter permanently suspends Donald Trump from platform
Panasonic
Panasonic's Augmented Reality Heads-up Display
PHOTO: Panasonic USA
Now playing
01:06
This tech gives drivers directions on the road in front of them
PHOTO: LG Display
Now playing
01:10
See LG's transparent TV
PHOTO: Twitter/@gregdoesthings
Now playing
02:06
Internet gets creative with empty iPhone boxes
NEW YORK, NY - JUNE 3: The Google logo adorns the outside of their NYC office Google Building 8510 at 85 10th Ave on June 3, 2019 in New York City. Shares of Google parent company Alphabet were down over six percent on Monday, following news reports that the U.S. Department of Justice is preparing to launch an anti-trust investigation aimed at Google. (Photo by Drew Angerer/Getty Images)
NEW YORK, NY - JUNE 3: The Google logo adorns the outside of their NYC office Google Building 8510 at 85 10th Ave on June 3, 2019 in New York City. Shares of Google parent company Alphabet were down over six percent on Monday, following news reports that the U.S. Department of Justice is preparing to launch an anti-trust investigation aimed at Google. (Photo by Drew Angerer/Getty Images)
PHOTO: Drew Angerer/Getty Images North America/Getty Images
Now playing
03:25
Google employee on unionizing: Google can't fire us all
Now playing
02:01
Watch 'deepfake' Queen deliver alternative Christmas speech
Now playing
01:42
Watch father leave daughter dozens of surprise Ring messages
PHOTO: Photo Illustration: Kena Betancur/Getty Images
Now playing
04:50
Zoom's founder says he 'let down' customers. Here's why
Now playing
00:48
See Walmart's self-driving delivery trucks in action
Now playing
01:25
This robotaxi from Amazon's Zoox has no reverse function
(CNN Business) —  

Congressional investigators on Friday called on Amazon, Apple, Facebook and Google to produce a sweeping list of financial records and business documents, opening a new chapter in a “top-to-bottom” antitrust review of the tech industry.

In letters to the tech giants, members of the House Judiciary Committee requested vast troves of evidence that could show whether the companies may have harmed consumers or competition.

The requests cover everything from Amazon’s acquisition of Whole Foods to Google’s ranking of search results. Lawmakers also sought communications by top executives; records generated as part of past antitrust and merger investigations; and detailed information on the companies’ internal decision-making.

“There is growing evidence that a handful of corporations have come to capture an outsized share of online commerce and communications,” said Rep. Jerry Nadler, a Democrat who chairs the committee. “It is effectively impossible to use the Internet without relying on these services, which now comprise the essential infrastructure for the twenty-first century. The documents requested will provide the Committee with a better understanding of the degree to which these intermediaries enjoy market power, how they are using that market power, whether they are using their dominance in ways that have harmed our economy or democracy, and how Congress should respond.”

The letters are not a subpoena. But the responses could help shape the direction of future hearings or possible depositions, according to a Democratic aide, and the committee could still compel further testimony with mandatory requests.

Spokespeople for Facebook, Amazon and Apple didn’t immediately respond to a request for comment. Google declined to comment on the committee’s document request, but referred CNN to a recent blog post by senior vice president Kent Walker saying the company has “always worked constructively with regulators and we will continue to do so.”

The requests underscore the scope of the committee’s investigation into Big Tech, and reveal a plethora of practices the lawmakers may consider to be anticompetitive.

Beyond headline-grabbing issues such as Google (GOOG)’s treatment of competitors in search and the Google (GOOG) Play Store, lawmakers requested documents that could show whether Google (GOOG) gives preferential treatment to online publishers that speed up article loading times using Google (GOOG)’s technology.

The committee also asked for information surrounding an effort to encrypt browser requests to websites, a technology that can better shield a user’s browsing patterns from prying eyes. Lawmakers asked Google for internal deliberations about whether Android and Chrome will keep collecting and using that browsing data even if the setting is turned on.

The committee sent a similarly detailed request to Facebook (FB), zeroing in on its relationship to Onavo, a data analysis firm that the social media giant bought in 2013. Critics say Onavo helped Facebook (FB) identify and eliminate potential rivals from the marketplace. Facebook (FB) is also being investigated over reports that the company has cut off some third-party apps from its data.

Meanwhile, Amazon (AMZN) is receiving scrutiny over its relationship to book publishers, alleged counterfeiters and third-party sellers. The lawmakers also requested that Amazon (AMZN) turn over internal communications about the data it may share or withhold from third-party sellers, an issue that arose in a previous hearing.

And the committee sought records from Apple (AAPL) that could reveal the decision-making behind the company’s App Store policies, including how Apple (AAPL) ranks search results on the platform, the removal of certain competing apps and how Apple (AAPL) determines the cut of revenue it takes from in-app purchases.

The letters come after the House Judiciary Committee’s antitrust panel postponed a hearing on data and privacy that had been scheduled for Sept. 12. The hearing — which would have been the third in the committee’s investigation into Big Tech — has not yet been rescheduled.

In a statement, antitrust subcommittee chairman Rep. David Cicilline called the requests an “important milestone.”

“We expect stakeholders to use this opportunity to provide information to the Committee to ensure that the Internet is an engine for opportunity for everyone, not just a select few gatekeepers.”