A U.S. House of Representatives panel on Friday demanded internal emails, detailed financial information and other company records from Amazon.com Inc., Facebook Inc, Apple Inc, and Alphabet Inc’s Google.

As Reuters reports, the committees’ letters seek by Oct. 14 internal emails over the last decade from Apple CEO Tim Cook, Amazon CEO Jeff Bezos, Facebook CEO Mark Zuckerberg and Alphabet CEO Larry Page, among others, about acquisitions.

Some days ago, the Texas attorney general led a group of 50 attorneys general from U.S. states and territories in a probe of whether Google abuses its market power in advertising.

The committee requested information from the companies’ executives on market share, competitors, their largest customers for specific products and documents from other investigations.

It asked Apple for information on the company’s decision to remove some parental control apps from its App Store and its policy regarding whether iPhone users can set non-Apple apps as defaults, among other concerns about its App Store.

The U.S. Justice Department is also investigating “whether and how” large tech companies in “search, social media, and some retail services online” are engaging in anticompetitive behavior.