HackerNews makes it hard to post anonymously. If you signup and try to post a lot of text or god forbid a Show HN you spent weeks building, it shadow bans you for at least five days. It forces you to wait before you can participate.
Lobste.rs doesn't allow signups without invitation. What if you don't know personally someone who is a user there to invite you?
Many Reddit channels don't let you post unless the account has 10-25 points of karma and is ten days old. This doesn't let you share something important with many people anonymously and quickly.
Do these policies of online forums make you feel excluded? Do you wish these sites ran differently? How would your ideal online forum run?