"Twitter has sold billions of archived tweets believed to have vanished forever. A privacy row has erupted as hundreds of companies queue up to purchase users’ personal information from the new database."<p>Is there actually any information in this? What do they mean by believed to be vanished forever? According to the BBC new article [1] "private accounts and tweets that have been deleted will not be indexed by the site."<p>Historically Twitter have been pretty good about ensuring, in their licences at least, things like deleted tweets are deleted even from external archives. It's what makes compiling a database of tweets - even for research purposes - quite difficult.<p>[1] <a href="http://www.bbc.co.uk/news/technology-17178022" rel="nofollow">http://www.bbc.co.uk/news/technology-17178022</a>