You can now change your own usernames! However the change will go to an administrator for review and approval. Frequent username changes are a hassle for everyone and won't be allowed. Username changes are generally going to need a good reason for approval.
There have been a few people who have accidentally registered with their real full name due to autofill. If you've accidentally registered with your real name and are still a new member please contact @damanding or @uituit by private message to request a username change. If you are an older member wishing to change your username for other purposes those will be decided on a case by case basis.