President Obama has decided to release OLC "torture memos" drafted between 2002 and 2005. In his statement (reproduced here), he cited "exceptional circumstances" justifying the memos' release (reportedly over the objection of some intelligence officials). He also said that those who relied upon the memos "in good faith" would not be prosecuted for their actions.
In releasing these memos, it is our intention to assure those who carried out their duties relying in good faith upon legal advice from the Department of Justice that they will not be subject to prosecution. The men and women of our intelligence community serve courageously on the front lines of a dangerous world. Their accomplishments are unsung and their names unknown, but because of their sacrifices, every single American is safer. We must protect their identities as vigilantly as they protect our security, and we must provide them with the confidence that they can do their jobs.
Going forward, it is my strong belief that the United States has a solemn duty to vigorously maintain the classified nature of certain activities and information related to national security. This is an extraordinarily important responsibility of the presidency, and it is one that I will carry out assertively irrespective of any political concern. Consequently, the exceptional circumstances surrounding these memos should not be viewed as an erosion of the strong legal basis for maintaining the classified nature of secret activities. I will always do whatever is necessary to protect the national security of the United States.