Tanker drivers at five of the seven main supply companies have voted in favour of industrial action over terms and conditions. Industrial action in fact means industrial inaction, ie, a strike. The union must give seven days' notice of its intention to call its members out on strike. In the meantime, the government and all the other pundits say to Joe Public "Don't panic. Be sensible."
So, what's the sensible thing to do? Fill up your tank, right? Right. So, everybody and his brother go out and, as a sensible precaution, fill up their tanks. Result? Petrol stations run out of fuel.
This isn't panic buying, of course, but the outcome is the same. Makes you proud to be British. And, as a bonus, you can always blame the government.