I awoke to the sound of my cell phone ringing. I opened bleary eyes to see it was still very dark outside. What time was it? After about 5 or 6 rings, the caller gave up. I was tired, but sleep would not come again. Annoyed, I decided I might as well see who it was that was bothering people at this time of night. The number was not one I recognized. I sent a simple text message asking “Who are you?” Almost immediately, I got a reply. But it was not my original caller. It was the automatic mailer daemon telling me that my message was undeliverable. The reason was because the number I tried to send it to…