Such redactions are only supposed to be allowed when authorized by Congress or for national security reasons.

FORBES: Why The Heck Is DHS Buying More Than A Billion Bullets Plus Thousands Of Guns And Mine-Resistant Armored Vehicles?

Ministers who for security or other reasons live in so-called 'grace and favour' homes will continue to pay council tax and tax on the benefit of living in this accommodation but will not receive this new allowance.

BBC: In full: MP expenses reform plans

One of Musharraf's aides, Saima Ali Dada, declined to say whether the former leader would appear in person before the judges or send a lawyer, citing security reasons.

WSJ: Pakistan Court Orders Musharraf to Respond

And, broadly, they fall into three categories: security reasons, reasons of prestige or status, and not to be minimized, bureaucratic momentum--scientists get bigger budgets, people get promoted, the military likes these programs.

NPR: Nuclear Weapons Not Appealing to All Countries

Sensitive Compartmented Information is information that not only is classified for national security reasons as Top Secret, Secret, or Confidential, but also is subject to special access and handling requirements because it involves or derives from particularly sensitive intelligence sources and methods.

CNN

It did secure one concession: for national security reasons, it can keep quiet about particular names that are either on or off the list.

ECONOMIST: Visa sanctions

The reasons for the attacks are irrelevant when it comes to evaluating whether or not a security force is capable of maintaining safety.

FORBES: Another Beating At Dodger Stadium

Whatever is collected beyond that is dropped into a vault at the end of their shift and later transported to a bank. (For reasons of security, the Port Authority will not disclose the name of the bank or the amount of money dropped into the vault.) Beyond simply collecting cash, toll collectors are required to document every non-E-ZPass customer by pressing relevant buttons on their monitor.

FORBES: Magazine Article

Here's the difference though: Whenever we cannot release certain information to the public for valid national security reasons, I will insist that there is oversight of my actions -- by Congress or by the courts.

WHITEHOUSE: President Obama: Our Security, Our Values

In the United States, Canada or New Zealand, the burden rests with the government to prove that documents cannot be disclosed for reasons of national security.

ECONOMIST: MI5