The government describes Upstream as follows: "Certain Internet transactions transiting the Internet backbone network(s) of certain electronic communications provider(s) are filtered for the purpose of excluding wholly domestic communications[,] and are then scanned to identify for acquisition those transactions [that contain communications] to or from... persons targeting in accordance with the applicable NSA targeting procedures; only those transactions that pass through both the filtering and the scanning are ingested into Government databases."

With this in mind, Wikimedia challenged the legality of Upstream, claiming it violated 702, the First Amendment and the Fourth Amendment.

The case against the NSA

The organization's case relied on three assertions - one, that Wikimedia's communications were so vast that they almost certainly traverse every international backbone link. Two, that the NSA conducts Upstream surveillance on at least one of those points. And three, the NSA must be copying and reviewing all text-based communications going through that point.

The judge agreed with the first two points, while the third claim formed the crux of the deliberation process.

Wikimedia's chosen expert, Scott Bradner, said that the NSA "most likely" copies all communications traveling across one of its surveilled points, and then filters it. "Even if the NSA were monitoring only a single circuit under upstream collection, it would be copying and reviewing at least some of Wikimedia's communications."

This was challenged by the NSA's handpicked expert, Dr. Henning Schulzrinne. While Schulzrinne does not know how the Upstream program works, he provided details on how the NSA could hypothetically avoid collecting Wikimedia's communications. Using traffic mirroring, the NSA could conduct surveillance "without intercepting, copying, reviewing, or otherwise interacting with [the communications of Wikimedia."

He said that, among other things, the NSA could blacklist all of Wikimedia's static IP addresses and not collect any data from those addresses.

Bradner admitted this was possible, but countered that it was "simply implausible as a practical matter given everything we know about Upstream collection."