The US Federal Trade Commission on Monday sent orders to Amazon, Facebook, Twitter, YouTube and other internet giants demanding troves of information about their data collection, ad practices, and user engagement.

The orders endorsed by four of the five FTC commissions were sent under the authority of a federal act that lets the agency conduct studies for legislators to have on hand when crafting relevant laws.

The FTC issued orders for nine social media and video streaming companies, requiring them "to provide data on how they collect, use, and present personal information; their advertising and user engagement practices, and how their practices affect children and teens."

Intended recipients were listed as Amazon, TikTok-parent ByteDance, gamer chat platform Discord, Facebook, Reddit, Snap, Twitter, WhatsApp, and YouTube.

Amazon made the list due to its popular Prime streaming television service, according to the FTC.

"The commission's study will lift the hood on the social media and video streaming firms to carefully study their engines," the FTC said in a release.

"The FTC wants to understand how business models influence what Americans hear and see, with whom they talk, and what information they share," the agency said.

Topics of scrutiny will include what social media and video streaming services do with information about users, as well as how they determine which ads people see, and their tactics for promoting engagement, according to the FTC.

Commissioner Noah Joshua Phillips said in his lone dissent that the orders are "an undisciplined foray into a wide variety of topics, some only tangentially related to the stated focus of this investigation."

The orders are "sprawling and scattershot" and so broad that they are likely to make it difficult for the FTC to glean insights that will be of use to Congress or others, Phillips contended.

Each of the companies is being told to respond to the order within 45 days of receipt.