I am short a couple dozen naked Feb 3 calls on a lot of affected tickers and almost had a heart attack when looking at one of them on my phone. Thankfully I was not in front of my computer at the time because I have no idea how my broker was managing my margin at open.
I just double-click the right-hand side button in my pocket, then double-check this is the correct card - thus unlocking the phone by me looking at it. Do it everyday without issues