Absent the elaborate use of personal counter-spy measures, preventing the collection of personal information is increasingly futile and doomed to fail.
These include closer co-operation between national intelligence agencies, the creation of an EU counter-terrorism chief, and measures that make it easier to trace terrorists who use mobile phones and e-mail.
The Prison Service is trying a variety of counter-measures, including drug-free wings where prisoners who promise not to use drugs are given additional privileges.