Who called from 6313063008

Called my cell phone. Hung up after 2 rings.

Called my cell phone, hung up after three rings.

Called my cell, hung up after one ring.....

Called my cell. Who are these mystery people?  Guess I'll never know, since I didn't answer, and don't plan on calling them back.

Called my cell. Hung up after one ring. Not going to call them back, since judging by the other comments here, they're probably a scam/telemarketer/etc.