It's always been like this. From the official secrets act where they could jail you just for revealing the date of the office Christmas party to D notices suppressing newspapers from publish stories the government thought were to sensitive. MI5 and MI6 acting totally without accountability, with the government not even acknowledging their existence. If anything, things have started to get more transparent now, with a freedom of information act, actual oversight and accountability for the intelligence services and less government. But the default position of the UK government has always been secrecy and the right to do what they want to protect the country.