Previously I've written about my admiration for the reference to Boticelli's Venus in a campaign aimed at curbing dangerous driving.
One of the things I realised recently is that the inference these drivers have small penises is meant to use the powerful psychological effect of shame to change their driving habits.
In this case the phrase "get your hand off it" infers masturbation. It harkens back to the call of mothers dissuading their progeny from handling their privates in public.
And it has also taken on another meaning in being used to suggest delusional language.