Given the huge amount of information hidden behind such shortened URLs, and given the popularity and number of these links, especially nowadays on Twitter, these services could see themselves being under permanent siege of hackers/crackers. Being able to manipulate hundred of thousands if not even more vastly distributed and popular URLs to point to a given site could be used for both, generating (lots of?) ad-revenue, or as a new form of DDoS-attack.

At the moment there seems to be no way around using these services (especially with services like Twitter), but in the medium/long run a solution has to be found if we don’t want to lose lots of valuable information.