This is the second time in the last week or two where someone calls but no one speaks. My cell phone tags the number, (803) 712-4583, as originating from Winnsboro, SC (between Columbia, SC and Rock Hill, SC)

It is an automated survey company.  If you dial it back it gives you an option to press 9 and remove your number from the list.

Report to  ... donotcall.gov
Multimillion dollar class action lawsuit against this and all other bacteria scum.
Calling them back, gives YOUR name and info.

Explain that one. How does merely CALLING give them ANYTHING? Answer, it DOESN'T!

Because it proves that your phone number is live. Some of these are computers dialing lists of numbers to determine which numbers are active. If you respond, they know they can sell your number to others so they can call and harass you, too. It's all about data. If they have your name and city and number, there's lots more they can find out quickly, and thanks to lax security everywhere, it doesn't take much to pose as another person and steal their identity.