"Overall, the audit found 2,776 'incidents' in which the NSA broke its own privacy rules while collecting information."These are violations of their own rules, which are arguably too weak. These are known violations, one can only imagine what the unknown is...
I encourage you to read the article, it is short and to the point.
The failures of any system will fall into these categories:
- Failures in specifying what is desired from the system. Including failure to protect the rights of the innocent.
- Failures in implementation - including allowing people access to information they should not have.
- Failures in use - including intentional abuse of power, and unintentional access.