Apparently some people have been sending naughty photos to nearby people using Apple’s AirDrop. While amusing, this could be startling to most people or down right perverted to minors.
Washington Post’s article about changing AirDrop.
To change your AirDrop settings, head into the Control Center — the menu that appears when you swipe up from the bottom of your screen. Just look for “AirDrop,” and it should tell you what your settings are. Tap the icon to turn off receiving completely, or you can choose to receive files from just your contacts or from everyone. (Those using Apple’s iOS 11 in beta can change these settings from the “General” menu of the settings app or by using 3D Touch on the Control Center panel that includes the switches for airplane mode and WiFi.)