Friends don't send friends worms
Giles Turnbull in Introducing Mac Worm X:
Imagine a mail message arrives from a friend, with an attached file. "I found this great Dashboard widget!" it says, "Try it out!"
User double-clicks. A widget is installed.
He goes on about how the widget could be evil and harm your system and files.
First of all, double-clicking a widget doesn't install it anywhere, it just runs it. Closing the widget makes it disappear from Dashboard entirely. But that's not the point.
Let's alter the situation a bit:
Imagine a mail message arrives from a friend, with an attached file. "I found this great application!" it says, "Try it out!"
I don't double click it because my friends send me URLs, not applications. The same is true for widgets. Moreover, an application has the same, if not more, devastating potential as a Dashboard widget, and it's been possible to e-mail applications since the Internet was invented.
So why all the fuss?