OS X 10.9.3 Bug hides '/Users' Folder, but an easy fix is available
For those who upgraded to OS X 10.9.3 and noticed that the /USERS/ Folder is gone, rest assured that it is still there, but you'll have to issue the following commands in Terminal in order to get it back.
The upgrade auto hides the /USERS/ Folder for unknown reasons. Â Just follow the below to get it back:
1.  Go to FINDER > APPLICATIONS > UTILITIES.
2.  Select the TERMINAL icon (as shown on the upper-right).
3.  Type in the following command: sudo chflags nohidden /Users
4. Â Tap Enter.
5. Â Type: Exit
6. Tap Enter.
7. That's it.