I personally don't like them (at all): the URL shorteners. These websites allow to summerize long URL's in short and tiny ones ...
... and on the fly will track users on Internet and hide the actual URL where you will be redirected to. I consider them a risk for privacy and potentially your computer's well being and eventually your bank account (when things turn out really bad).
When I notice a question or answer using a shortened URL, should I (we) edit it or shouldn't I worry so much? Is there a SE policy on this?
I'd even vote for SE blocking shortened URL's or automatically replacing them with the initial link address.
Wikipedia has a nice article on URL shortening.
These are the 'analytics' of the link I removed shortly before writing this post. (Just adding a
+ at the end of the URL does that).