If you click the PGP lock icon by the clock, you will see the option "Exit PGP Services" option.
If you want to hide this, you can do so with the PGP Policy with a PGP Server (Symantec Encryption Management Server).
To do so, go to the policy in question that your user is controlled by. To do this, click on the Consumers tab, then Consumer policy and click on your own policy.
Next, Click the "Desktop" settings. Then under the General tab, look for the option "Hide the option to disable PGP Services":
If you want the users to be able to exit their own services, uncheck the option for "Hide the option for disable PGP Services".
If you leave it checked, then users will not have the ability to hide the services.