In order to help you with this, we'd have to know which distribution you're using, as the location for installed software can vary a lot. We'd also need to know your install method. Did you use a package manager, or install from source?
Also, user access has less to do with the location of the software, and more to do with the file permissions.
But generally, you install things as root, to the root file system, and all users have access to it. If you install something as a regular user, to your home directory, only that user account will have access.
It will help if you can give us the output from a few commands:
First, as root:
ls -l `locate utorrent | grep bin`
Note that those are backticks, NOT single quotes.
Give us the output from that and we can go from there
Also, just FYI, it's generally not a good idea to run regular programs as root. The permission system is in place to prevent user-level programs from affecting the OS. When you run user-level programs as root you render the permission system useless.