Once Intelligence Services (and by association, governments) start to get 'worried', the shutters go up and the disinformation starts. There are two very current examples; although one turns out to be quite old, but has only recently come to light.
As expected, the British Government are pressing hard for much of the evidence in the Gareth Williams murder inquest to be heard in secret. It now appears that the murdered MI6 man also had links with the US National Security Agency (NSA) and had returned from the USA not long before his murder. So it's not just the Brits who are worried. Keep a careful eye on the inquest when it gets fully underway in a couple of weeks time.
The 'secret justice' debate in the UK has also recently brought to light what appears to be an awful example of what happens when the security services close ranks - often to cover up their own shortcomings and mistakes. Here we have what seems to be monumental failures by the CIA (pre-9/11) which are then covered up with what is known as State Secrets Privilege to influence the British courts. Stuart & Margaret Bentham were the recipients of 'secret justice'. Plenty is beginning to emerge, if you are interested.
Is it surprising that conspiracy websites have sprung up over the years? The problem is, they are sometimes self-defeating. The participants become so paranoid, that they risk ridicule. The moment that happens, their story (however true) becomes devalued. And that plays straight into the hands of those who would see them silenced or marginalised.
My own knowledge of the security services (through association rather than participation!) led to events that could easily lead to paranoia. Once you know that you are in a room or sitting around a table with people who in another role are members of various security services (British, French, German and possibly Middle-Eastern) the feeling becomes quite surreal. They are people who wear 'two hats'; pretending they do not know what the others do, while all the time (of course) they do!
When my home phone was bugged, I wasn't quite sure who the interested parties might be. No, I'm not getting paranoid. It was in the days when the technology was not as sophisticated as today and rather gave itself away.