I did below. PHP is a joke of a language/platform (and I say this as someone who has six years of professional PHP experience), but that wasn't my point.
The point was: PHP is dog slow, Facebook solved that particular problem with a gargantuan engineering feat, deleting photos is trivial by comparison, therefore they either do not give a crap or it's somehow beneficial to them to keep them around forever.
The point was: PHP is dog slow, Facebook solved that particular problem with a gargantuan engineering feat, deleting photos is trivial by comparison, therefore they either do not give a crap or it's somehow beneficial to them to keep them around forever.