In addition, presumably you do not mean mounting it silently; you mean mounting it and launching some application to show its contents.
No, I specifically said that I only wanted it mounted, NOT that I wanted it to automatically start something from it.
I'm surprised that the software wants to mount something when there is nothing to mount, if you connect a USB standard cable that ends only into a charging circuit, (or for example a device like a light or a fan) there cannot be any USB communication, so there should never occur a mounting attempt. I can see the problem however if the device is something like an MP3 player that uses the same connection for power and for communication with the device. Still it is a good habit to always (try to) unmount any removable medium. So I would still prefer automounting it if necessary, even in this case. But normally I think you would (should) not see this behavior if all you do is drawing current from the USB port.
However I agree that its completely acceptable to automount the moment the user first clicks on the icon of the recognized device, in fact that would be the perfect solution, even in the rare case you plug something (a memory device) in which you don't want to open.
It perfect because it does not force the user to find out how to mount the device, nor does it ask extra effort from the user to mount the device.
My argument is just that the user should not be forced to do anything extra just to start the automount procedure, (I have seen distro's where you actually needed to open a terminal, browse to the device map, and manually execute a mount command) but clicking on the icon to do whatever the user wants to do (open, browse etc) is fine, and is expected behavior for most users.
Obviously i'm not "pleased" by the behavior you describe of LXDE, but I think you already knew that. You can create a broken implementation of almost everything, and this behavior seems broken indeed.
Well, at least your reacting is a factual one, not just "blah blah", thanks for that.