When my phone is in my pocket, I tend to hold it like a gadget security blanket, and I sometimes end up squeezing the side buttons. This was never a problem until I got the iPhone X, which has some new features tied to those side buttons. More specifically, if you press and hold both the power button and a volume button for a few seconds, your phone will call 911 and/or your designated emergency contacts.
I’ve never done this, but a friend of mine had an iPhone X in a car phone mount and it slid down during the drive, pushing both buttons, and automatically called 911.