Don't worry though they have a fool-proofing auditing systems in place to prevent abuse of the intelligence they have intercepted on US "persons".

I am always amazed at the double claim the NSA makes:

1. That they have a great auditing system that catches abuses.

2. That the auditing system shows that most NSA employees are honest because they have caught very few abuses.

The two claims do not support each other. These two alternatives would be more convincing:

1. That the auditing system is great and thus we have caught millions of abuses.

2. That the auditing system is easy to bypass and therefore we have caught very few abuses.

The very fact that Snowden could take what he did, in the way in which he did, and that they still don't know the extent of data copied shows that their auditing systems are easy to bypass.