Online anti-selves are social media profiles and testimonials that people might think are you, or were created by you, but, in fact, are nothing more than bot-collected data-dumps and fraudulent attempts to use your name for maximum profit. These anti-selves frequently go on to form lives of their own, mirroring and paralleling your own in horrible, dirty ways.
Even people who do not use the internet, or who have died, are not immune. There is no escape from the networked Anti-Self.