It’s unwise to just pull a USB stick out of the opening of the Mac when you’re done with it. The official way is better.
Remove USB correctly
Many people regularly use a USB device, such as a USB stick. However, sometimes people forget to shut down the device properly before it is removed from the computer. Correct closing is very important. This prevents information from being lost.
To remove a USB device on Mac (from macOS X 10.9 Mavericks):
- Click the Finder (via the icon on the Dock).
- The name of the USB device can be found under the ‘Locations’ or ‘Devices’ section in the left menu.
- Click the Eject Button
after the device name.
The name of the USB device now disappears from the overview and can be safely removed from the computer.