in the context of modern London though the problem with that joke isn’t even that its “dark humour”, its just a bit old/outdated! – My parents generation of hippies were in hyde park saying stuff like that (there is even monty python sketches about it from that era) and its not even that valid for modern English society, despite its many other faults. Plus its difficult trying to “make people laugh” when their kids might be serving in “iraqistan” etc..
Mre importantly where nigboat is he is competing with loads of people already doing heavy political stuff, and the other side of British “free speech” is folk just ignore stuff they disagree with so if he wants to get a funny video will have to be more subtle 馃槈
