I also received a called on my personal cell and then work number from 312-273-1439 ( caller ID = GB Marketing CO). Wow..... same thing... sign for security system.
Received a call from this number a few minutes ago. My non-English answering machine picked up the call. The call left an automated message asking to place a security sign in my yard and install a free security system. I ignored it totally, and I will block this number. Obviously a scam.