Gatekeeper's Dialog
Here is the dialog users see when they attempt to mount a disk image that is not signed with an Apple certificate:
"Adium" has not been signed by a recognized distributor and may damage your computer. You should move it to the Trash.
"Adium" is on the disk image "Adium_1.4.4.dmg". Safari downloaded this disk image today at 11:06 AM from adium.im."
Dustin Curtis, on the new Gatekeeper dialog in OS X Mountain Lion. It's a great feature to protect your Mac from untrusted software, but I agree that the dialog should be better thought out. Most people would not even understand what it means to begin with.