The idea
Repeal section 58
Why is it important?
Outlaws possessing an immensely wide range of information ("of a kind likely to be useful to a person committing or preparing an act of terrorism").
This could conceivably be any information, as any information could in theory be "useful". There is no requirement of any evidence that it was intended in fact to be useful, was downloaded in connection with terrorism, or anything of that kind.
There is no defence that on a balance of probability it was not in the person's possession with a criminal intention. If someone wrote up the encyclopedia's hundreds of articles on explosives, tactics, terrorism tricks, detection methods, police procedures – for example Wikipedia et al.
Someone obtained and had in their possession the scientific and operational research to do that article writing. "Material likely to be useful"? Of course! So… arrest them for having edited the article or viewed it on their computer? (Viewing is deemed to be possession/control in cyberlaw as the browser saves a copy to the computer)