Who called from 6615768797

This phone number calls here at least 7 - 10 time a week. They either hang up after three rings, or if I answer it, it also hangs up.
Who the hell are these idiots?

Calls and there is no one if you pick up and leaves no message if you let ring out.

It's the World Wildlife Fund looking for donations.

Like others, I get calls from 661-670-2618 frequently, but there is no one on the line & never a message.

4-Jan-2013 6:51pm
661-670-2618
callerid: Newhall CA
===============
Ring 6 times then hang-up