Very strange the number shows up like this, however for me it was a legitimate call from my internet provider Time Warner Cable (they left a message). They were following up on a complaint I made on Twitter.
Update: I spoke with a very useful tech at TWC and inquired about the odd phone number. He explained that the call center he worked out of (not specific to Time Warner) spoofs a six-digit number to prevent getting overloaded with callbacks.
His particular call center was located in Greensboro. Cary's use of 336-336-XXXX numbers is apparently a coincidence.