It's related to "Big Brother" in Ghost in the Shell: Stand Alone Complex. From a Japanese list of terms used in GitS,
Nickname of satellite-ring communication interception network. A communication interception network that American Empire's National Reconnaissance Office is proud of, which intercepts any communication circuit, including internet, wireless, telephone, etc. The amount of incoming communication data freezes operator androids and makes the terminals within 1km radius go down even if Public Security Section 9's facility is used. "Big Brother" was introduced in a novel Nineteen Eighty-Four, and it's a secret code for an surveillance system called "ECHELON".
but the word "Echelon" itself is only mentioned in its movie counterpart, Ghost in the Shell: Stand Alone Complex - The Laughing Man. From a Japanese site comparing the anime and its movie counterpart,
Also, the term "Echelon" - a satellite-ring communication interception network - was spoken by Aramaki. It makes it easier to understand what "Big Brother" is about.