Re: Why now
"Newspapers" like the 'i' are largely to blame, running headlines like "Petrol rationing", when no such thing was happening.
*Technically*, they can get away with saying that because some filling stations were putting limits on how much they would sell you.
I saw the initial reports of the very few filling stations having supply issues, but the next morning, last Friday, the Daly Mail printed the headline "Britain Running on Empty". By that evening, it's was coming true because that (and maybe other media outlets) click-bait headlines caused the panic buying.