Why is everyone on Facebook so paranoid about their privacy?

There’s a line in Desperately Seeking Susan where Madonna (Susan) reads aloud the diary of Roberta, the bored housewife she has swapped places with: ‘Couldn’t sleep. Went into kitchen. Gary came in, turn off light. Gary left. Finished birthday cake.’ Then she exclaims: ‘Pages of it; it’s got to be a cover — nobody’s life could be this boring!’

A related naughty thought often comes to mind when I see my chums worrying on Facebook about The Man stealing photos of their cat wearing rabbit ears or their own preferences in caffeinated beverages. If there is a stealthy cabal of shadowy figures seeking to make puppets out of us — mere paper dolls capering powerlessly at the whim of our faceless masters! — why do people with such dull lives believe they are in any way of interest to would-be Dr Evils? Or are cats-in-rabbit-ears fascinating code for something intriguing that only I haven’t been let in on?