People are only human. They are fallible. They are weak. They occasionally make mistakes, get greedy or use poor judgement. Some are just bad.
Any significantly large organization made up of thousands of people is going to have problems. It doesn’t matter if it is business, religious, government, military or intelligence. There are always going to be some abuses. Much of human history is about finding ways to reduce the level of abuse. Open and transparent democracy has proven the be the best way to reduce abuse by the government, and even that sadly fails frequently.
It implies that it is possible to put safeguards on a large organization that has enormous amounts of power and few outside checks. This contradicts everything we know about human nature, and history.
If you give a huge group of people huge amounts of power there will be abuses. Power corrupts.
You can only try to reduce the amount of abuse to an acceptable level. The best ways to do that are reduce the level of power to the minimum amount necessary and providing as many checks as possible. You want watchmen, men watching the watchmen, and people auditing the watchers.
Simply trusting the NSA to be made up of only “good people” as it continues to grow in size and scope with almost no oversight can’t be an option.
Update: LOVEINT! Like I said, there will ALWAYS be abuses.
Photo by Andrew Price under Creative Commons license