The following is the text of a comment I attempted to post to an excellent post on visitmix.com discussing The Evils of URL Shorteners. I think Hans had some great points, and the comments afterward seem generally thoughtful.
This is a topic which I happen to think is extremely important, for both historical and Internet-governance reasons, and hope to see a real discussion and resolution committed to by the community. Thanks for reading.
I agree with the problem completely, if not with the solution. I was a long-time user and enthusiastic supporter of tr.im back in the day (up to what, a couple of months ago?) It was obvious they were doing it more or less as a public service, not as a revenue-generating ad platform; they were apparently independent of Twitter, Facebook and the other "social media" services (which is important; see below) and several other reasons. Unfortunately, since the First Law of the InterWebs seems to be that "no good deed goes unpunished," they got completely hammered beyond any previously credible expectation, and, after trying unsuccessfully to sell the service off, are in the process of pulling the plug.
I think it's absolutely essential that any link-shortening service be completely independent of the large social-media sites like Facebook and Twitter, specifically because of the kind of trust/benevolence issues raised in the earlier comments. We as users on both ends of the link-shortening equation might trust, say, Facebook because their policies at the time led us to believe that nothing dodgy would be done in the process. I think the events of the past few weeks, however, have conclusively proven how illusory and ill-advised that belief can be. Certainly, such a service would give its owner a wealth of valuable marketing data (starting with "here's how many unique visitors clicked through links to this URL, posted by this user"). They could even rather easily implement an obfuscation system, whereby clicking through, say, a face.bk URL would never show the unaltered page, but dynamically rewrite URLs from the target site so that the shortener-operator could have even MORE data to market ("x% of the users who clicked through the shortened URL to get to this site then clicked on this other link," for example). For a simple, benign demonstration of this, view any foreign-language page using Google Translate. (I'm not accusing Google of doing anything underhanded here; they're just the most common example in my usage of dynamic URL rewriting.)
Another security catastrophe that URL shorteners make trivially easy is the man-in-the-middle exploit, either directly or by malware injected into the user's browser by the URL-shortener service. The source of such an attack can be camouflaged rather effectively by a number of means. (To those who would say "no company would knowingly distribute malware", I would remind you of the Sony rootkit debacle.)
So yeah, I resent the fact that I essentially must use a URL-shortener (now j.mp/bit.ly) whenever I send a URL via Twitter. I also really hate the way too many tweets now use Facebook as an intermediary; whenever I see a news item from a known news site or service that includes a Facebook link, I manually open the target site and search for the story there. That is an impediment to the normal usage flow, reducing the value of the original link.
Any URL-shortening service should be transparent and consistent with respect to its policies. I wouldn't even mind seeing some non-Flash ads on an intermediate page. ("In 3 seconds, you will be redirected to www.example.com/somepage, which you requested by clicking on w.eb/2f7gx; click this button or press the Escape key on your keyboard to stop the timer. If you click on the ad on this page, it will open in a new window or tab in your browser.")
Such a service would have to be independent of the Big Names to be trustworthy. It's not for nothing that "that zucks" is becoming a well-known phrase; the service must not offer even the potential for induced shadiness of behaviour.
I'd like to see some sort of non-profit federation or trade association built around the service; the idea being that 1) some minimal standards of behaviour and function could be self-enforced, and especially 2) that member services that fold would have some ability/obligation to have their shortened link targets preserved. This way, there would still be some way of continuing to use links generated from the now-defunct service.
Since the announcement that the Library of Congress will be archiving ALL tweets as an historical- and cultural-research resource, and contemplating a future in which it is expected that URL-shortening services will continue to fold or consolidate, the necessity and urgency of this discussion as an Internet-governance issue should have become clear to everyone. I hope that we can agree on and implement effective solutions before the situation degrades any further.