I was going to gloat about how I don't use something like yik yak, but then I realized I'm anonymous here, and that HN employs heavy handed moderation to deal with near anonymous chat.
Except that you aren't anonymous here. You are pseudonymous which is very different because you have a consistent identifier allowing people to interact with you and review your history and posts and attack you. When you are anonymous it would require significant effort to identify a user using lexical analysis or the like and the false positive rate would likely be quite high.