Caller id: security first
they wanted to place a free wireless security  system in our home and signage in our front yard.. He laughed and mocked us when we asked to be put on their do not call list.

Wasn't able to answer my phone & caller didn't leave a voice mail message.

Got a call from these new scammers yesterday while I was out; they left no message but based on the caller ID their MO is rather obvious.

Repeated calls from 415-723-2690.  I keep requesting to add my number to the "no contact" list, but I continue to get these calls.  When I answer, they hang up immediately.  I have never spoken to an actual person, but I have followed their prompts to have my phone number removed from their data system.

Called several times. I finally answered and didn't hear a response until I had already hung up. I'm guessing it's a scam.