In dealing with anti-spam techniques, URL shorteners are used to obfuscate bad links all the time.
There are only 2 use cases:
- Used to actually shorten links, say in emails. To me, this isn't a valid use case. I always dump the whole URL.
- Tracking and analysis. For example, Twitter injects t.co links into every Tweet with links for tracking purposes. In the case of Bit.ly, click analytics is their business model (http://www.enterprise.bitly.com).
Compare:
https://maps.google.com/maps?saddr=1120+Avenue+of+the+Americas,+New+York,+NY&daddr=Yankee+Stadium,+East+161st+Street,+Bronx,+NY&hl=en&ll=40.792239,-73.955154&spn=0.10371,0.157757&sll=40.802895,-73.924084&sspn=0.103693,0.157757&geocode=FcHhbQIdhRqX-ynJiS1XVVjCiTFFAV5BZkL2Ug%3BFZgBbwIdnPiX-yEIHppV2cNASSlxaedaLPTCiTEIHppV2cNASQ&dirflg=r&ttype=dep&date=01%2F15%2F13&time=1:00pm&noexp=0&noal=0&sort=def&mra=ls&t=m&z=13&start=0Sites providing their own short urls isn't much of a problem as far as I can see.