Google is not the only entity getting thier hands on Twitter's Tweet archive. The Library of Congress is also getting access for preservation purposes.
"The Library of Congress is the oldest federal cultural institution in the United States and it is the largest library in the world. The Library's primary mission is research and it receives copies of every book, pamphlet, map, print, and piece of music registered in the United States. Recently, the Library of Congress signaled to us that the public tweets we have all been creating over the years are important and worthy of preservation.
Since Twitter began, billions of tweets have been created. Today, fifty-five million tweets a day are sent to Twitter and that number is climbing sharply. A tiny percentage of accounts are protected but most of these tweets are created with the intent that they will be publicly available. Over the years, tweets have become part of significant global events around the world—from historic elections to devastating disasters.
It is our pleasure to donate access to the entire archive of public Tweets to the Library of Congress for preservation and research. It's very exciting that tweets are becoming part of history. It should be noted that there are some specifics regarding this arrangement. Only after a six-month delay can the Tweets will be used for internal library use, for non-commercial research, public display by the library itself, and preservation."