A press release from April 14, 2010, announced that the Library of Congress acquired the entire archives of Twitter tweets.
Have you ever sent out a “tweet” on the popular Twitter social media service? Congratulations: Your 140 characters or less will now be housed in the Library of Congress.That’s right. Every public tweet, ever, since Twitter’s inception in March 2006, will be archived digitally at the Library of Congress. That’s a LOT of tweets, by the way: Twitter processes more than 50 million tweets every day, with the total numbering in the billions.
The Archives include, for example, the first ever tweet, President's Obama tweet about winning the 2008 presidential elections, and many more.
[I]f you're looking for a place where important historical and other information in digital form should be preserved for the long haul, we're [the Library of Congress] are it!