Guide to DIY Wiretapping

Geeks are Sexy writes "ITSecurity.com has a nice piece this week on how wiretapping works and how you can protect yourself from people who wants to snoop into your life. From the article 'Even if you aren't involved in a criminal case or illegal operation, it's incredibly easy to set up a wiretap or surveillance system on any type of phone. Don't be surprised to learn that virtually anyone could be spying on you for any reason.'" Maybe I'm on the wrong track here, but I guess I assumed that wiretapping now happened in secret rooms at the telco, and not by affixing something physically to a wire in your home, but I'll definitely be aware next time I hear a stranger breathing next time I'm stuck on hold.

It was..

[f8l_0e]

The official, albeit illegal kind do occur at the telco, at least these days. Before modern switching a residential tap would have be the way it was done.

What a load of crap.

[chill]

The 80s called and their want their wiretapping tech back.

This is great if you're worried about the neighbor kid listening in, but not for anyone serious. Wiretapping is done at the telco level and you can't tell you're being tapped. In the digital age there is no clicking, breathing, voltage drops or any other indication. There is a big long checklist when implementing a CALEA node for making certain there is no way the target can tell they're being monitored.

Re:voltage drop

[Anonymous Coward]

The "professional" wiretap uses a buttset. These have bed-of-nails clips for monitoring without leaving any particularly obvious traces (a small hole is made through the sheath of the wire, that is all, no cutting or stripping is involved).

They also have both a regular and monitor mode. The regular mode makes it work like a normal telephone, with about 600 Ohms impedance, causing a voltage drop. The monitor mode has 100+ kOhms impedance, which will cause a voltage drop low enough to be indistinguishable from a moisture leak (happens all the time on analog phone lines).

Here's [tiptopelectronics.com] a nice one you can buy right now!

Beige boxing: a blast from the past!

[Anonymous Coward]

You mean there's a device you could attach to a phone line to listen to a call? Amazing!

For people in the know, there's an easier method to listen in on calls which is only detectable by the phone company: a Direct Access Test Unit [wikipedia.org] or DATU. Find one of these "secret" numbers on the exchange your victim is on and you have the ability to snoop on their calls using the phone company's own test equipment. Messing with these numbers is also a very quick way to go to jail, but you sorta run that risk with an illegal wiretap anyway (unless you work in the Executive branch).

Yes, it is done at the telco

[rob_osx]

As a embedded software developer at a major telco equipment manufacturer I can verify that when the government wants a wiretap, they can do it easily at the telco. Several times telcos came to us and said "the government has asked for a wiretap how can we use your equipment to comply?" The process to do the wiretap was the same used to setup a conference bridge, which digitally duplicates the DS0 or T1. The government could then get a digital copy of all voice/data of the lines.

More useful

[Thelasko]

Why only phone conversations, when a laser microphone can listen in on all conversations. They are also easy to build. [instructables.com]

Re:Hear a stranger breathing?

[Thelasko]

If someone is dumb enough to leave the microphone connected on an intercept phone, they deserve to get caught.

You raise a good point. Using a plain speaker is risky, because it can potentially double as a microphone. Telephones have a duplex coil which prevents this from happening.