When running the horizon client via the command line:

Horizon Client Command Usage

You have an option to supply a username/password.

The problem is, that as long as the connection to the remote desktop is open, the username/password argument is displayed in clear text in task manager under the processes list and any user with permissions to the desktop can gain access to that username and password.

On the other hand, when entering the data with the Horizon Client prompt, you don't see any such data. Anyone know a way around it?