Terror?
"David Davis described the theft as extremely serious. "Terror investigations are extremely complex and depend on vital intelligence and evidence based on phone records," he said."
Which has what to do with the data on the stolen server, unless there's some terrorists out there logging all their own calls?
"Hello, you've called the Fundamentalist Terrorist hotline, for all your terror support needs. Calls may be monitored or recorded for training and quality assurance purposes. Press one if you have carried out, or are planning an attack....."