They call several times a day; I don't pick up. The machine kicks in and immediately the person (sometimes male, sometimes female) says, "Hello, my name is Blah Blah, I'm not trying to sell you any.." at which point my machine goes BEEP because they start talking as soon as the machine clicks, right over my outgoing message; so the beep makes these very intelligent people think someone's hung up on them.
I'm not picking up the phone for anyone not bright enough to outwit an answering machine.

I agree they are pigs.

I picked up the phone and the guy (with an American accent) said, "Hi, this is John and I'm not calling to sell you anything. May I speak to....". That's when I promptly hung up.

is this number associated with LEVEL 3 COMMUNICATIONS, LLC - MD?

Indian lady called with indian accent and asked if it is Mrs. Clark's residence?

A Hundi accent called and pretended muslim saying slam and calling from AT&T head qaurter informing you about that you won lottery. But was total fraud to get personal information

301-637-7544 was on my caller ID on Tuesday Feb. 28, 2012 at 7:05pm, the caller did not leave a message.  The same number called again Thursday March 1, 2012 at 6:28pm, I answered the caller did not say anything I told whoever was on the other end not to call my phone number again!

Found a call from 301-637-7544 on my business phone list of missed calls, Wednesday morning, October 19th, 2011.  Caller left no message.