In the place where Great Britain used to be, a silver-haired granny didn't card the purchaser of a goldfish and as a result was fined fifteen hundred bucks and tagged like a migrating seal.
It's a good thing the bobbies are cracking down on this, using elaborate undercover stings to catch underage goldfish sales. I mean, if you let grannies sell goldfish to just anyone, next thing you know there'll be riots in the streets! It'd be a madhouse!
Besides, it's a known fact that goldfish are a "gateway pet" and that most everyone who keeps a rabid Bengal tiger started off with one of these seemingly-harmless fishies.
(H/T to SurvivalBlog.)