Terrorrism Act 2000 Section 58 – effectively makes most of the population criminals, and potentially enables the state to use this law against any person that the executive does not like, perhaps purely for political reasons.
Consider the following two scenarios
Someone who never visits london might possess a diary which has a copy of the London underground in its cover. As we know from the events of 7/7, a map of the london underground is useful to terrorists in planning terror.
Or perhaps someone might simply be interested in science and buy a chemistry book which might explain chemistry of explosives etc.
This law has already been used to lock up a teenager merely for possessing a copy of the "Anarchists Cookbook", a resource which is freely available online and is still being sold by amazon today.
For reference, this is the current text of Terrorism Act 2000 Section 58
(1) A person commits an offence if—
(a) he collects or makes a record of information of a kind likely to be useful to a person committing or preparing an act of terrorism, or
(b) he possesses a document or record containing information of that kind.
(2) In this section “record” includes a photographic or electronic record.
(3) It is a defence for a person charged with an offence under this section to prove that he had a reasonable excuse for his action or possession.
(4) A person guilty of an offence under this section shall be liable—
(a) on conviction on indictment, to imprisonment for a term not exceeding 10 years, to a fine or to both, or
(b) on summary conviction, to imprisonment for a term not exceeding six months, to a fine not exceeding the statutory maximum or to both.
(5) A court by or before which a person is convicted of an offence under this section may order the forfeiture of any document or record containing information of the kind mentioned in subsection (1)(a).
(6) Before making an order under subsection (5) a court must give an opportunity to be heard to any person, other than the convicted person, who claims to be the owner of or otherwise interested in anything which can be forfeited under that subsection.
(7) An order under subsection (5) shall not come into force until there is no further possibility of it being varied, or set aside, on appeal (disregarding any power of a court to grant leave to appeal out of time).