This morning’s Observer column.

Infectious diseases, says the World Health Organisation, “are caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi; the diseases can be spread, directly or indirectly, from one person to another.” Quite so. Just like Facebook addiction, which also spreads from person to person and has now reached pandemic proportions, with more than a billion sufferers worldwide.

The Facebook pathogen doesn’t kill people, of course, for the good reason that dead people don’t buy stuff. But it does seem to affect victims’ brains. For example, it reduces normally articulate and sophisticated people to gibbering in the online equivalent of grunts. Likewise, it obliges them to coalesce all the varieties of human relationships into a simply binary pair: “friends” v everyone else…