It’s an unbelievable admission. The nation’s most advanced and sophisticated intelligence organization will continue to delete data they’ve been ordered to keep because they “don’t know how” to stop.
When the Electronic Frontier Foundation (EFF) discovered the NSA had illegally intercepted client data, they sued the NSA to restrict the data collection.

As their case against the NSA began to move forward, it was discovered through a Justice Department email slip-up, that the NSA was actually deleting evidence of their wrongdoing.
Despite the fact that there were several open cases forbidding them from performing these actions, the NSA moved forward with massive evidence purges.
In fact, a Federal Intelligence Surveillance court had ordered the NSA to retain any data collected under both executive authority and Foreign Intelligence Surveillance Act authority, but the NSA went ahead and got rid of the evidence anyway.
When pressed on the matter by a federal judge, the DOJ (working to represent the NSA) said they “misunderstood” the order and deleted data based on their interpretation of the ruling.
When the EFF learned of this, they filed a restraining order against the NSA and were told by the DOJ and the NSA that they were unable to comply with the request because to do so would shut down a significant portion of the NSA’s data collection program and compromise national security.
As reported by the Daily Caller:
A requirement to preserve all data acquired under section 702 presents significant operational problems, only one of which is that the NSA may have to shut down all systems and databases that contain Section 702 information, NSA Deputy Director Richard Ledgett wrote in the agency’s response, along with its intention to file a follow-up explanation.
According to Ledgett, NSA systems are too complex for such a request, and following through with the court’s order would have an immediate, specific, and harmful impact on the national security of the United States.
Currently, the NSA continues to delete data and ignore the court ruling while putting national security over the Constitutional freedoms of individuals in the republic.

Lee ADDS: Maybe if some miscreant were arrested and jailed the stonewalling and illegal acts would be curtailed!