How to prompt user confirmation on Mac from Windows/Linux VNC connections? is there a way to ask confirmation from the user when someone try to connect via VNC from a Linux or Windows based PC to his Mac?
I succesfully connected via VNC from Mac, Linux and Windows, without any problems, but only in Mac to Mac connections the user of the computer I want to access is prompted for confirmation to share is screen. When I connect from Windows or Linux PCs, I just have to type the VNC password and I'm in, without the user knowing that there's someone watching his screen (only if he's fast enough to see the small change in the binocular icon).

I'm using the native VNC server of Mac, activating the Remote Management option in sharing preferences. I use also ARD to manage software updates, that's why I can not disable that option. But ARD is installed only on the Macs of the support team (wich are few), most of the team uses Linux based PCs to provide IT suport in our college.

Is there a way to warn the user or ask for his permission to acess his screen using the native Mac VNC/Screen Sharing when connecting from a Windows/Linux PC??
System preference => Sharing => Remote Management => Computer Settings 
Check the box: VNC viewers may control screen with password: 
And allow access for only the users needing access. That should do the trick