They believe he has stored a massive amount of data obtained from hacking some pretty large mainframes, including police records and social security numbers, outsourcing might seem a cheap idea to those organisations using it but it does seem placing your data on-line means accepting the risk of losing it at some stage.
I know I have stated it before but its a simple concept and worth repeating, if you don't put your data on publically accessible equipment then you make the risk of loss pretty much reduced and this is done by utilising static lines to your data that don't connect to the public telecommunications/data networks, such lines are expensive but when you weight the potential damage caused by data loss it seems a sensible undertaking, most banks and govt institutions in the UK uses such lines and that's why you wont hear of any large data breaches bar those caused by human interfacing with the data directly or copying.
I think they are scared of just how much data he has in his possesion, after all who might have a few dark secrets on the police computer that Gottfried might know about and be ready to exploit to aid his situation.