A/Prof. Patrick Stokes has just published Digital Souls: A Philosophy of Online Death (Bloomsbury, 2021):

Social media is full of dead people. Untold millions of dead users haunt the online world where we increasingly live our lives. What do we do with all these digital souls? Can we simply delete them, or do tehy have a right to persist?… This provocative book explores a range of questions about the nature of death, identity, grief, immortality, the moral status of digital remains and the threat posed by AI-driven avatars of the dead. In the digital era, it seems we must all re-learn how to live with the dead.