Like so many of "those sayings", mixture, that's where it comes from.
It's not from my lot - we're more into fish than poultry, and anyway - as you say - neither is relevant for computing.
I spend some of my time fixing computers for the good folk of the villages, and often their problem is caused by browser hijackers and PUPs - as provided "free of charge" by certain well known organisations (they require you to untick the box if you don't want the proffered goodie). One delightful octogenarian lady had so many search toolbars that she didn't have much browser screen left to work in.