There was an opt-in survey in from YouGov & The Economist that seemed to show a fifth of young Americans denied the Holocaust. The Economist ran a piece on it.
Well, Pew Research did a random sampling and found completely different and far less worrying results.
Alternative analysis: only youngins do a little trolling
edit: but do not troll about the holocaust, please.
Pretty good chance this was /pol/ doing exactly that
it’s mostly unintentional, article basically says it’s paid surveys where people select random answers without even reading the questions to get a reward.