Called and just said hello, hello - then hung up - would not leave any other message and if I don't know who's calling, I sure as hell ain't picking up
Called, left no message.
When I called back from another phone a man answered. I began explaining that I'd gotten a missed call on my cell from that number, and he rudely interrupted saying, "no problem, we'll call back later, thanks!" and hung up. It's like he was in a hurry to get off the phone in case I had some kind of software "tracking" him or something.