Lawful Intercept(ion) Primer Part I – Introduction

Welcome! Please comment and leave me a note telling me what you like and what you'd like to see more of. Sign up to my RSS Feed!
This entry is part of a wonderful series, Intercept»

Many readers have asked me to clarify what Lawful Interception is, why it is needed (or not), how it is implemented, and what are my thoughts on the subject. This post series will be a stream of thoughts, facts, and figures about Lawful Interception and any/all discussion is welcome.


To start with, the term Lawful Interception refers to the recording, analysing, or processing of communications.  While historically referring to Telephone calls, especially calls over the Publicly Switched Telephone Network, and thus called "wiretapping", the term today includes communications in any form, including:

  • Telephone calls
  • Cellular telephone calls
  • Internet communication
  • Wi-fi
  • GPS signals
  • and generally any other form of communication (electronic or not).


As in most developed countries, interception of communications in the USA is generally illegal.  It is generally illegal for someone to listen-in on your phone calls, read your email, and open your regular mail.  It is also generally illegal for someone to run network analyzers on your access point or to trace your connections.

Due to the ever-growing need of most States to have more Intelligence, an ever-changing compromise was worked up and eventually codified into Law.  Perhaps the best example of a listening system in the world is the US National Security Agency (NSA), an agency that for years did not "officially" exist, and that was vilified in many movies, stories, books and rumors.

While originally constructed to listen-in on foreign military communications, it is generally presumed that the NSA does listen-in on domestic communication, especially when it does so under permission granted to it by US Law.  This article does not intend to talk much about the NSA, focusing instead on law-enforcement agencies.

In general, in the United States and most western countries, Lawful Interception requires a court order signed by a judge. However, it is important to note that one major exception to this rule is the the allowance to any network services provider to do the needed LI in order to protect their own networks.

In the next blogs in this series, I will discuss why Lawful Interception is needed (or not), how it is implemented, and some of my thoughts on the subject.