I almost want to start sending these links to people at work- just to see what they do. If they actually click on them, then that's bad.
If I could track clickthroughs like you can with Bit.ly (you could always just sketchify a Bit.ly link) then you could do some security testing to see who will click on anything.
Ah, but with URL shorteners, people are already clicking on anything! Which I'm guessing is the point to this whole exercise.
That said, the reason we've come to tolerate shorteners is that there's an implicit network of trust in the way they're used on Twitter. We trust that someone we follow isn't going to put a goatse behind that bit.ly because we know enough about them to believe they wouldn't (or at least we don't think they'd risk a massive loss of followers for it).
So by the same reasoning, if you send a ShadyURL to a co-worker, if they know you, they probably trust you won't be sending them anything malicious. Though I suppose the smart thing for a recipient to do would be to double-check with you that you sent the right link.
