Before obtaining transactional data about multiple unidentified users of communications or other online services when trying to track down a suspect, the government should first demonstrate to a court that the data is needed for its criminal investigation.
This principle addresses the circumstance when the government uses subpoenas to get information in bulk about broad categories of telephone or Internet users, rather than seeking the records of specific individuals that are relevant to an investigation. For example, there have been reported cases of bulk requests for information about everyone that visited a particular web site on a particular day, or everyone that used the Internet to sell products in a particular jurisdiction.
Because such bulk requests for information on classes of unidentified individuals implicate unique privacy interests, this principle applies a standard requiring a showing to the court that the bulk data is relevant to an investigation.