My grandmother is a heavy user of the Shelf icons on ChromeOS. Her computing habits seem to be very spatially oriented; she knows where her mail icon should be. If the mail icon is missing, she gets very confused.

Unfortunately it is very easy to click and drag icons off the Shelf, esp. if the user's clicks are more like smeary click-drags than crisp single-clicks (poor dexterity). This results in support calls to me, in which I help her bring the icons back onto the Shelf from the app manager.

It would be nice if I could right click a Shelf icon, click on a contextual menu item e.g. "Lock this icon", which would make that shelf icon immune to accidental drag-offs unless the shelf icon is explicitly unlocked first.