Morons but that's Millwall. I've seen Man City and Liverpool fans mocking Munich air crash, people sing about Scousers in poverty and there's definitely been some Jimmy Saville statements directed at Leeds.
Name, shame and ban. More than effective enough. The Wednesday lads mocking Sunderland's Bradley Lowery apparently were known for being idiots and were banned from every footballing pub in Sheffield, as well as from games and supporters groups.