Hacker News Reader

You could measure the number of incidents that didn't happen before the TSA was formed, though

Even the deadly hijackings it was formed to prevent wouldn't ever happen again, since the passengers would fight back now

Between 1968 and 1972, over 130 commercial aircraft were hijacked in the US. No hijackings have been reported in the US since 2001.

.... what happened between 1972 and 2001?

Take a look at the graph in my first link. Looks like dozens and dozens of hijackings.