I don't understand why people make anything of "real names" policies. They just want the users to have real looking names. They don't actually have any way to force real names. So it's a non-issue. There's no oppressed person in a police state signing up for Facebook that reads a EULA and concludes "well, Facebook said I have to reveal my true identity, I guess that's the way it is."
They can and do enforce the real name policy. If they suspect your name isn't real (via algorithm or user reports) they will freeze your account until you send them scans of government ID confirming your name. I have a friend with an unusual name, and she's had to go through the process twice thanks to harassers flagging her.
This is a fairly significant and under discussed problem. Rush Limbaugh is probably safe from harassment... that dude commenting in some political group is not so immune. This creates an interesting chilling effect.