Like you Jon,I reckon 'banter' and a bit of piss-taking are quite all right and can be funny.

Usually Norwich supporters are reasonably well-behaved and manageable.
There are only a few extra Police officers stationed around Carrow Road when there's a big match on.

But I believe some clubs have notoriously rumbustious supporters and a few who are downright nasty, which spoils the Game and brings it into disrepute.

Mocking opposing fans about the tragic death of a young man in an air accident is nothing short of evil though. Ignorant louts.