The Library of Congress is going to archive โ€œtweets.โ€ All of them:

Have you ever sent out a โ€œtweetโ€ on the popular Twitter social media service? Congratulations: Your 140 characters or less will now be housed in the Library of Congress.
Thatโ€™s right. Every public tweet, ever, since Twitterโ€™s inception in March 2006, will be archived digitally at the Library of Congress. Thatโ€™s a LOT of tweets, by the way: Twitter processes more than 50 million tweets every day, with the total numbering in the billions.
We thought it fitting to give the initial heads-up to the Twitter community itself via our own feed @librarycongress. (By the way, out of sheer coincidence, the announcement comes on the same day our own number of feed-followers has surpassed 50,000. I love serendipity!)
We will also be putting out a press release later with even more details and quotes. Expect to see an emphasis on the scholarly and research implications of the acquisition. Iโ€™m no Ph.D., but it boggles my mind to think what we might be able to learn about ourselves and the world around us from this wealth of data. And Iโ€™m certain weโ€™ll learn things that none of us now can even possibly conceive.