Someone got my cell number off the internet?

How is this possible? Any way to block them with iphone? They were also threatening to hack my computer

Added (1). No, i did NOT post my number ANYWHERE, and it can't be found on anything i've posted on or put up. I just don't put it on the internet. This is why i'm so confused, my cell number isn't linked with anything I've done the internet

Somebody you know has probably posted it on Facebook, MySpace or Twitter… Or all three.

Hope this helps.