I was just posting on Github how I wanted to keep a particular icon for a now unsupported extension---as it's been removed from Mozilla's add-on site.
The thought then popped into my head: "why do I even still have it after two Firefox updates?"
This then raised the question "Should Firefox forcefully remove known, unsupported extensions?"
From a security perspective, my gut tells me this would make sense, but I don't think it would be a very Mozilla thing to do.

What do you guys think? Would it make sense to do this or would it be better to simply leave folk to their madness? Would giving them a notification be worth it (e.g. pop-up or special highlighting in about:addons)?
P.S. - I'm talking about current extensions and not pre-WE ecosystem. The extension I'm being nit-picky about is StumbleUpon and it was ported over to WE. Because they abandoned ship, the extension has since been removed from add-on site.
