If you try to search a Twitter feed, you can only go so far. Seven days, as a matter of fact. 30, if you’re a business. Now a company called Datasift is offering access to two year’s worth of archival tweets.

The BBC reports: “Access to the archive has been billed as a way for companies to harness discussion online to predict future events such as mass protests – as seen during the Arab Spring – or the rise and fall of stock prices.”

Privacy advocates are worried about what might be drudged up from accounts. A good old 140 character rant might come back to bite you in a job interview. More likely, though, will be the scenario that’s playing out all over: your data being mined for advertisers. Tweet about the Oscars and maybe you’ll start seeing ads to buy Academy Award-winning DVDs. Tweet about your dad, and maybe you’ll get suggestions for a Fathers Day event… or a book deal.