Here's one message I've had from Synaptic (the package manager for Ubuntu):
[URL=http://img511.imageshack.us/my.php?image=synapticvw0.png][IMG]http://img511.imageshack.us/img511/103/synapticvw0.th.png[/IMG][/URL]
To clarify it reads:
***********************************
Warning
You are about to install software that can't be
authenticated! Doing this could allow a malicious individual
to damage or take control of your system."
***********************************
Sums the matter up rather, doesn't it?
In other words, Canonical has instituted a system whereby its own package manager is delivering software that it cannot vouch for.
Can anyone in his right mind imagine Apple trying that on with paying customers? And--fair's fair--to give Microsoft credit, could you imagine going to Windows Update and getting such a message? It wouldn't fly.
There would be outrage if Apple or Microsoft did this, but because Canonical distributes the software of "freedom" it's different rules for them.
I'm sorry, package managers are clunky; many of the repositories are barely maintained horrors; the whole system wouldn't even be needed if the current Linux desktops were designed properly, so you had drag-and-drop installation as on OS X instead of dependency hell. And last but not least no software vendor should be making available to its users, through its package manager, software that it can't vouch for in terms of quality or even security--and no reputable one does.
The Problem of Staying Updated