I just got  two calls in a row this morning from that number and the person on the other end of that number. Like left me one sigh voice and sound of my answering machine. These numbers always say Name Not Found on my caller id and the previous annoying number was the usual 000-000-0000, but I was shocked & surprised that this time they used a weird random fake number like 431-907-06431. My guess is that they are people that uses some kind of internet or computer program, but that they could make up and use any phone number they chooses than they call random people houses with their tricks & pranks and scams. I really hate it and think its so annoying.