Kim is right. The console extensibility story was not built with security/"show me what's relevant" scenarios in mind. As Dean suggests, you could fiddle with file permissions to prevent unauthorized admins from being able to launch the executable, but that wouldn't prevent the user from seeing the extension in the console. I'm assuming you're dealing with a shared machine scenario (e.g. multiple admins remoting into the site server), as if you are dealing with different machines per user, the obvious answer is to only install the extension on the personal machines of those admins that should have it.