“Back in the days of the Cold War, spies found ingenious and unusual ways to communicate with each other, hiding their communications in plain sight, whether encrypted or not. For instance, an intelligence agent (spy) might contact his case officer (handler) by placing an ad in the personals section of the local newspaper. This practice, it seems, continues today.

On or around May 8, the following personal ad appeared on the Internet classified ad site Craigslist. (It has since been removed.)

For mein fraulein

Mein Fraulein, I haven’t heard from you in a while. Won’t you
call me? 212 //// 796 //// 0735

If you actually called the number, up until a couple of days ago you would have heard this prerecorded message (MP3). It’s a head scratcher to keep you National Security Agency analysts occupied in your spare time. Each block of numbers is repeated twice; but below I have transcribed them only once for clarity.

Group 415
01305 60510 12079 04606 50100
93000 08203 90130 94069 01207
81080 17028 01706 90220 73038
01401 70150 15073 00402 00680
12013 12510 00540 04091 01401
30150 86022 09608 10660 02082
05507 00020 00000 02208 30290
08022 01200 40710 13065 02709
40190 29014 02200 80020 11083
07300 30260 19000 00700 00000
86

You used to hear broadcasts not unlike this on shortwave radio all the time, stations which broadcast nothing but numbers all day. Nobody has yet come forward with an answer as to what exactly these stations were broadcasting, or to whom, or what was the point of the messages. If anyone does know, they likely can’t say because it’s classified information.”

http://www.homelandstupidity.us/2006/05/31/the-212-796-0735-mystery/