Who posted Number Station phone numbers to Craigslist in 2006? [video] | Hacker News Reader

Who posted Number Station phone numbers to Craigslist in 2006? [video]

youtube.com

21 pointsmmastrac12 comments

The only explanation that makes sense to me is art/creating this for fun.

The conventional explanation for number stations is spy business, see https://en.wikipedia.org/wiki/Numbers_station

I think GP means to suggest that the 'leaked' ones were spoofs for art/fun.

Yeah, but why would a spy agency set up a line with an automated recording and then post the number on craigslist? Might as well post the numbers themselves on craigslist. Or you know, your own website.

It is not about publishing the content - it is about being able to read the content without anyone tracing that you are doing so. The web is non-viable for that goal. Phone lines are a little better. Radio is even better than that. This is also why they would publish information in newspapers back in the day. The goal is not to protect the content, it is to protect the people who read it.

Trivia: in the 50s the British MI5 developed simple techniques for detecting when they were near to someone listening to a particular radio frequency. https://en.m.wikipedia.org/wiki/Operation_RAFTER

Or not. From the article's talks page:

"This article should be deleted. It is entirely based on Peter Wright's Spycatcher book, which is a regurgitation of old public domain stories considerably embellished by Wright's vivid imagination."

Interesting. At that time it wasn't easy to build a receiver so sensitive that it could detect from distance a receiver local oscillator, which radiates only by mistake (bad design, insufficient screening, ...) as it's not connected to any antenna. However I don't understand this:

"By accident, one such receiver for MI5 mobile radio transmissions was being monitored when a passing transmitter produced a powerful signal which overloaded the receiver, producing an audible change in the received signal. The agency realized that they could identify the actual frequency being monitored if they produced their own transmissions and listened for the change in the superhet tone."

Why would they have to do that? The monitored LO frequency already tells which frequency the receive is tuned on, by being 455 (sometimes 460) KHz below or above (usually above) the one is being received. If you know that frequency you already know which one the other receiver is tuned on. What am I missing?

BTW, those values are just industry standards. When building a radio one can use whichever IF frequency they want: either standard 455KHz or 10.7MHz but also very different ones if one has the necessary parts to build filters (coils, xtals and xtal/saw filters, etc). Very old TV sets are great sources of parts that can be used: IF coils (TV IF is usually around 39 MHz), SAW filters, demodulator chips and complete tuners that could be used to build VHF/UHF receivers.

For example:

http://www.rfcandy.biz/communication/sprec.html

https://mekweb.eu/?lang=en&q=download-details&f=84

> Yeah, but why would a spy agency set up a line with an automated recording and then post the number on craigslist?

I suppose that it's easy to monitor who calls a line if you only expect a single user to sporadically call.

If you convince a small mob to call your line, suddenly whoever is monitoring that line will have orders of magnitude more people to verify.

An even larger mob visited the Craigslist listing itself.

The second half of the video is about the people who ran this project and that it was indeed done for fun. They gave a talk at DEFCON. They had a website explaining everything[1]

[1]: https://web.archive.org/web/20100413212320/http://projectevi...

Oh, thanks, I've watched only the initial part and thought it's an open "mystery".

Reply on news.ycombinator.com