WASHINGTON (Reuters) - The Federal Trade Commission is seeking information from Facebook, Twitter and other social media and video streaming companies about how they use the personal information that they collect on their users, the U.S. agency said on Monday. In addition to Facebook Inc and Twitter Inc, the orders requesting data were sent to Facebook subsidiary WhatsApp, Amazon.com Inc, China’s ByteDance unit TikTok, Discord Inc, Reddit Inc, Snap Inc, and Google subsidiary YouTube LLC. The FTC is seeking to learn how the companies collect data on users, how they decide which advertisements to show and how algorithms are used, among other information, the agency said in a statement. It is also seeking information about how the companies’ practices affect children and teenagers. The companies have 45 days to respond to the orders, which are usually used to generate policy or recommend legislation. In a joint statement, two Democratic members of the commission, Rohit Chopra and Rebecca Slaughter, and one Republican, Christine Wilson, noted their impetus for the order. “Never before has there been an industry capable of surveilling and monetizing so much of our personal lives,” they wrote. “Social media and video streaming companies now follow users everywhere through apps on their always-present mobile devices. This constant access allows these firms to monitor where users go, the people with whom they interact, and what they are doing. ... Too much about the industry remains dangerously opaque. Discord said it looked forward to answering the FTC’s questions. “We make no money from advertising, selling user data to advertisers, or sharing users’ personal information with others. Instead, the company generates its revenue directly from users through a paid subscription service,” a spokesperson said in an email statement. None of the other companies immediately responded to a request for comment.