Received a call at our business. No response then hung up. I have kept track in the past of number that do not acknowledge you when you answer the phone. After a couple of months of this, I started receiving advertising calls "targeted" to our type of business from the same numbers. Apparently when they call and do not respond, they have someone taking down what type of business you have, then sell your number to businesses who sell in that area.
Also notify the FTC with these phone numbers. I would think they should get them shut down or find the owners.
The FTC encourages consumers to file a complaint whenever they have been the victim of fraud, identity theft, or other unfair or deceptive business practices. They can do it online, or by calling the FTC's Consumer Response Center at 1-877-FTC-HELP (1-877-382-4357).