I occasionally get random "trust this computer" prompt on my iPhone. This is NOT when connected to a computer via USB. It has happened at home, but also happened elsewhere. I reply "no", but I can't say for sure that I haven't accidentally or without thinking replied "yes" in the past. When it occurs when not connected by USB (presumably, WiFi or Bluetooth) it begs the question: trust WHICH computer?! You'd think it would occur to Apple by now that the user might want to know what computer they are being asked to trust... I think I've gotten this on my Apple Watch as well. Sorry for being vague, but it didn't just happen. (But has happened within the past month.) Thought of it after reading the recent news around fake Apple ID password prompts. To be clear, these are not password prompts, but just "trust this computer?"