In the absence of good porn, logging on to facebook and masturbating to pictures of your more attractive "friends". Has proven to be more popular than porn for those lacking morals.
Facebook Quickies occur when careless people post provocative pictures.
"Dave is appearing offline because he doesn't want you to interrupt his Facebook Quickie"
"Sarah must want guys jackin' it to her image because she is wearing a bikini in almost all her pictures"