I don't think that's off topic at all. Few years ago (ok there was no HN in that day) this [1] wouldn't happen either.
[1] http://travel.usatoday.com/flights/post/2011/11/locked-in-la...
[1] http://travel.usatoday.com/flights/post/2011/11/locked-in-la...
These kind of events can and routinely escalate just due to fear alone.
It is also often at the expense of specific colored individuals.