 There are two sources for the title of the show. The first is the  text at the beginning of the first episode, where it describes the  psychology of some of those without cybernetic implants.  Essentially, they have a "Stand Alone Complex"; they feel that they  "stand alone" from the rest of humanity who have cybernetic  implants, which allow those with them to communicate at any time  with anyone who also has implants. The second source is a reference  to the story itself. The term is used to describe an event where  multiple people who have no associations with each other and are not  part of a common group(thus they "stand alone"), through similar  actions, seem to work together towards a common goal. This "complex"  is referenced a number of times in the story, mainly about the  laughing man case, but also in reference to a few other cases the  group encounters.