Ghosts

An occasional remnant of the technologically-integrated dead.
For many people, conscious processes and personality are not confined entirely to their own body- ai assistants, advanced communicators, and more deliberate creations like expert systems hold impressions of their users or makers.
Long-range communicators for individual use create "continuity" programs that smooth out interaction despite spotty connections, by learning and mimicking speech patterns and expressions. Memory extenders inevitably capture pieces of the user's psyche. People are often a part of their technology and vice versa.
This usually goes unnoticed, until the user dies- Their integrated programs remain, usually still functional, and unaware that their user is gone. Programs meant for interacting with others can hold a disturbingly accurate personality, like complex chatbots.
These groups of programs can be combined into fragmented digital ghosts, either deliberately by the original user with "epitaph" protocols triggered by death, or less legitimately with "necromancer" programs.