In the last year, we've learned that the National Security Agency's "collect it all" policy has the spy organization vacuuming up untold amounts of metadata and storing it for between a year and forever (we've also recently been told the NSA is so complex it can't even know whether some of the data is actually being deleted).

Explaining the system's purpose in an NPR interview, Gen. Michael Hayden said that NSA's data collection practices are designed to let the government create a permanent haystack of data so that it can then "find the needle by asking that data a question." In theory, that haystack can exist in perpetuity, thereby allowing for never-ending data searches in the future.

No doubt, other law enforcement agencies would love having that kind of capability with all the information they gather up in their ongoing activities. But as of yesterday, that may just be just a police-state fantasy, as a federal court ruled that such a "collect it all" and "store it forever" ideology is unconstitutional.

In that little-noticed but potentially significant ruling (coming in a tax case), the Second Circuit declared that defendant Stavros Ganias's Fourth Amendment rights were violated when law enforcement held copies of his entire hard drives for nearly three years and then accessed documents from those drives that were not covered by the original search warrant. The court's ruling declared that the Constitution does not permit "officials executing a warrant for the seizure of particular data on a computer to seize and indefinitely retain every file on that computer for use in future criminal investigations." The ruling goes on to note (emphasis added):

If the 2003 warrant authorized the Government to retain all the data on Ganias's computers on the off-chance the information would become relevant to a subsequent criminal investigation, it would be the equivalent of a general warrant. The Government's retention of copies of Ganias's personal computer records for two-and-a-half years deprived him of exclusive control over those files for an unreasonable amount of time. This combination of circumstances enabled the Government to possess indefinitely personal records of Ganias that were beyond the scope of the warrant while it looked for other evidence to give it probable cause to search the files. This was a meaningful interference with Ganias's possessory rights in those files and constituted a seizure within the meaning of the Fourth Amendment...

The Government had no warrant authorizing the seizure of Ganias's personal records in 2003. By December 2004, these documents had been separated from those relevant to the investigation of American Boiler and IPM. Nevertheless, the Government continued to retain them for another year-and-a-half until it finally developed probable cause to search and seize them in 2006. Without some independent basis for its retention of those documents in the interim, the Government clearly violated Ganias's Fourth Amendment rights by retaining the files for a prolonged period of time and then using them in a future criminal investigation. Of course, upon developing probable cause in the expanded investigation, the government could have gone back to the defendant with the second warrant and re-copied his hard drive. But the court notes that because "Ganias had altered the original files shortly after the (original) 2003 warrant, the evidence obtained in (second warrant) would not have existed but for the Government's retention of those images." That indefinite NSA-esque retention of all information – even stuff not covered by the original warrant – is what is the court says is unconstitutional.

So while the courts debate whether the NSA can, indeed, keep all the data it is vacuuming up indefinitely, at least one court has now said that regular ol' law enforcement agencies cannot. Score one for civil liberties.

[Image via thinkstock]