Source: Harry Guinness, HowToGeek.com, April 3, 2018
Facebook has always had a real names policy, where you agree that your profile name is “the name [you] go by in everyday life.”
Obviously, you can type in a fake name, and you may get away with it for a while. But it isn’t allowed, and it can cause you trouble.
The entire foundation of Facebook is that it’s a site where real people interact with each other without hiding behind anonymous usernames and blank avatars. It’s why, despite Facebook’s many problems, they’ve never had the same level of abuse and trolling that Twitter and Reddit get.