A woman reported a male Economist to the flight crew as a potential terrorist, because he was doing a differential equation on the plane. You know, the sort of equation that Economists use to calculate derivatives.

https://preview.redd.it/w8jcqdd3ivr51.png?width=739&format=png&auto=webp&s=704b9cfeb7b8f0daa4e48c520cdaf573ec0ed027