By now, you have probably heard that USDOJ has issued a subpoena to Twitter asking for various types of information from the Twitter accounts of Julian Assange, Bradley Manning, Rop Gongrijp[sic], and Birgitta Jonsdottir. Here is the subpoena. It was originally issued under seal, which means that Twitter could not tell anyone that it had received this subpoena. Twitter could have simply complied with the sealed subpoena and none of the people listed above even would have known about it.
Instead, Twitter apparently made a motion to unseal the subpoena. It had standing to do this because the sealing of the subpoena infringed upon its own ability to interact with its customers/subscribers as it sees fit. The motion to unseal was successful and Twitter notified its users about the subpoena. It is now up to the users to move to quash the subpoena itself.
Twitter really didn’t have standing to quash the subpoena directly because Twitter doesn’t have much stake in its customers’ privacy. This is in contrast other business models, such as WikiLeaks itself. If WikiLeaks receives a subpoena to divulge information about its users (the leakers) it would have standing to oppose that subpoena because the WikiLeaks business model is centered around protecting the privacy of its users. Take that away and you have basically destroyed the raison d’etre for WikiLeaks and upended its entire business model.
Not that WikiLeaks would be likely to win such a motion to quash. As Judy Miller and Matt Cooper found out to their chagrin, if law enforcement can show a particularized need for a piece of info and that there is no other viable means to obtain that info, the court is going to uphold the subpoena.
However, WikiLeaks would have standing to contest on the merits in a way that Twitter probably does not.