This add on was requested here (http://xenforo.com/community/threads/block-url-shortened-links.31370).
When attempting to post a message containing a blocked word (currently configured with around 300 URL shortening services), an error is displayed.
This add on, in theory, could also be used to block other words too.
Upload contents of the upload folder to your library folder.
Install through Admin CP using provided XML file.
Check readme.txt for details on how to add/remove blocked words.
None of this add on is configurable currently using the Admin CP. Refer to the readme.txt file if you want to block other words.
To Jake Bunce for being wonderful as always.