after further searching I've discovered some of the things that people could be prosecuted under the old (2000/2001) terrorism act include
Failure to leave a cordoned area immediately when ordered to do so by a constable in uniform
Failure to leave premises, which abut or are wholly or partially within a cordoned area, immediately if ordered to dos o by a constable in uniform
Failure of driver or person in charge of a vehicle which is in a cordoned area to immediately move the vehicle if ordered to do so by a constable in uniform.
Failure to stop (Power to stop and search vehicles and pedestrians)
Provides instruction; invites another to receive instruction in weapon training.
Collect, record or possession of information or articles likely to be of use to Terrorists. (I should imagine that many journalist could theorectically could be convicted on that one if they're researching on terrorist based stuff)
Just found this quote too
Information gathered with the help of the Crown Prosecution Service (CPS) and Institute of Race Relations provided details of 13 convictions.
It emerged that three of the convictions related to Irish republicanism and four to the Irish loyalist movement.
Two stemmed from a Sikh terrorism case and one involved Tamil terrorism.
Only three related to some form of Islamic terrorism.