A community moderation model is used on the catalog. You can click the flag icon under a comment or list to report ones you think are inappropriate. When 3 separate users report something, the comment is flagged as contains offensive materials and/or may be removed if it violates the Terms of Use of the catalog.
You can go to My Settings in your account to hide content flagged as offensive.
You can report inappropriate usernames to your library using the Ask Us a Question form.