I don't know how they would decide what broke copyright laws. At least in the US, you are allowed to use a limited amount of copyrighted material ... such as a picture from a movie ... under certain circumstances, which (IIRC) memes qualify under.
Ahh but a very important point here.. it's not UK that made the law.. it's the EU and this is exactly the kind of thing that people voted Brexit for.. that we have been forced to follow stupid rules made up by unelected idiots which are almost always in favour of anyone apart from the UK..
We can't sell our apples because they are the wrong size, we can't fish our own waters but others can, we have to buy BUY milk while a lot of ours gets poured away.. the list is endless..
I postulated at the time to AMericans who didn't agree with Brexit.. I said.. how would you feel if some other country were telling you what to do, and not do, making your rules and taking loads of money and giving little in return.. People seemed happy to entirely ignore that point but for many Brexiters that was the point.