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.
Another use of VoIP to disconnect a phone number from a physical location, this time apparently for an intelligence purpose (although this seems an anachronistic way to deliver a ciphertext). "Group 415" might be a reference to the area code in San Francisco, where Craig's List is most popular. There is also a song in the recording. Identifying the song might aid analysis... The voice is clearly sampled.
