A better option:
obfuscated minified links outright.
They've already become a spammer's best friend, and they're otherwise a completely user-hostile experience. Is it nuts if I want to know where the link I'm clicking is going to take me before I go there?
In addition to abuse, here are some other justifications for banning shortened URLs:
- Abuse (oh, did I already mention that?).
- Pointless. This isn't Twitter, you have plenty of characters to post an actual link.
- Linkrot, when the services inevitably shut down.
- Privacy, because one of the advantages of these services—tracking user behavior—can just as easily be seen as a disadvantage.
- Standing on the shoulders of giants: Yahoo Answers and Wikipedia already ban the use of shortened URLs. What better examples could we have?