Before the Freedom of Information Act came into power in 2005, relevant files were released under the 30-year rule as a complete body.
Now, however, the releases are done piecemeal, meaning that secret material relating to controversial issues from three decades ago may escape public attention permanently.
Hmmm, so according to that we can see the uncontroversial stuff immediately, (assuming it wont cost too much – and we know to ask for it), but the other stuff can be kept secret forever. Where as we used to at least see it after 30 years. oops.