From the settings app, use Message or FaceTime preferences to add numbers to a your devices block list. I have been facetiming my elderly mother nightly for a long time. When we upgraded to i OS 7 we started to have trouble, she said she was not receiving my calls.
Finally last night some random (and angry) woman answered my FaceTime call and told me not to call her anymore.
With telephones you can block things from the phone company as their software is programed to allow this.
With i OS 7, it also can be programmed to block calls from a caller that you don't want to hear from again.
What’s more, the lawsuit points out that Apple has the technology to incorporate such a feature, as evidenced by a pertinent software patent originally filed by the company in 2008.