https://www.pcgamer.com/epic-on-steam-friend-importing-the-user-can-do-with-their-data-as-they-please/

Last week, users discovered that the Epic Games Store was copying a Steam file that contained their friends' user IDs and other data. It did this before prompting users to choose whether or not to import their Steam friends into the Epic launcher.

Epic explained that while the client did copy the file, nothing was sent to Epic unless the user opted in, at which point hashed friend IDs were uploaded. Epic CEO Tim Sweeney said that the early copying was a problem that would be fixed.