If you force everyone to use their real names be aware:
1) People are afraid to ask questions that will make them look bad in front of friends/colleagues.
2) It’s common for people to search for website activity of their boss, colleagues, recruits, friends, and relationship partners.
3) Many languages use letters and diacritics that don’t appear in the English (or even the Latin) alphabet.
4) The EU’s right to be forgotten law technically requires you to delete the entire history of contributions of inactive members after a specific period of time.
5) People often change their names when they get married.
6) People often used shortened versions of their names in everyday life. Should they use their name on the passport or the name they most commonly go by?
7) Some cultures have multiple names or naturally use pseudonyms.
8) Many people will share the same name. What should they do?
9) There isn’t much data to support the supposed benefits of using real names (seeming more professional, greater trust, and better familiarity are largely unproven).
10) …Yet, in many industries, seeing a response from ‘KitchenDad44’ would seem strange.
11) If your data is hacked, your problems are much worse with real names.
If you want real names, I’d suggest you use a nudge (default) but don’t force it. Be prepared for each of these challenges.
(p.s. Jeff Atwood blogged about this problem in a post a few years ago I can’t find, sorry Jeff).