Several years ago, sometime after 9/11, I was going through immigration back into the US and someone, obviously an excited tourist, had pulled out her digital camera (yes, back when we took pictures with dedicated cameras and not phones) and started taking pictures. Again, she was clearly an excited tourist, and it's a bit difficult to see how taking pictures of an immigration line is going to aid some major terrorist plot.
Rules are rules, but they treated her like she had just escaped from a SuperMAX. They could have nicely brought her aside, asked her to delete the pictures, and sent her on her way, but they put on their asshole suits right away (no I am not claiming that there were beatings). You might remember that at this time the security regulations US airports were changing about every 3 days and it's not as if most people, especially foreigners, are exactly aware of what the latest and greatest versions are. I never am and I live in the US.
They gotta know their job is mostly bullshit. What's a little bullshit without a bit of fun to keep it lively?