New Internet terminology I just thought up:
Bimodal poster: Person on the Internet who is always talking about one of two topics: A) the complete catastrophic misery of their life, a darkness from which they will never emerge, or B) how they are the most brilliant person who ever lived, how hot and amazing they are, and their ever-growing pile of accolades and sex partners. They will never post about anything else, especially not about anything other than themselves.