When mobile gadgets the Apple connect to the new computer or other device to gain access to the files, you will need to confirm that you trust the connected device. The screen displays a window with buttons to “Trust” and “trust”. If the iPhone or iPad is password protected, you need to unlock it to see the message.
A trusted computer can access the files and settings of the iOS device. This PC can be synchronized with the gadget, import pictures, get access to videos, contacts and other content until the user has disconnected the device. Content will not be available until the user enters the password (if enabled) and confirm that they trust the connected computer.
If you have indicated that you do not trust the connected computer, iPhone and iPad will charge, but connected Mac or PC will not be able to access its content.
If you choose to “Trust” the computer will have a status of trusted, until you cancel this status or will not erase data from the device. If you chose “Not to trust”, this message will appear each time you connect the device to the PC.
Below on how to cancel the trust for all computers on your device with iOS 8 and later.
Step 1: Go to Settings of your device, then choose tab General –> Reset.
Step 2: Select the “Reset geometrici”.
Step 3: After this action will also reset your settings geolocation and privacy. The next time you connect to the computer, a message box prompts you again to do the computer is trusted.
To cancel the trust for all computers, you can also select “Settings > General > Reset > Reset network settings”. After this action will also reset your network settings.