Everybody is shortening URLs these days. While this saves spaces in Tweets it has several disadvantages for the user: you don’t see the domain that this link refers to. And you know that for certain clicks on the short URL are recorded and data-mined. Just have a look at my public bit.ly timeline. I check there often … pure vanity.
You might remember my hobby project Tweet Curator which allows the filtering of tweets that have certain domains. Now the next extension of this concept would be to also expand those pesky short URLs and use the referred domains for blocking too. There is NO hiding any more!