GUUUUUUH I’m so tired of answering this question. The sources are not hard to find if you look.

Copied from my other comment:

There was a great segment on Adam Ruins Everything about security theater; they’ve run tests of the security systems in place at airports and gotten all kinds of things through that are supposedly banned. But it’s not reported, because as long as people believe those systems work then it actually helps them work (if…