How to block unknown numbers from calling your mobile?

I know you can download an app to block certain people from calling you but unknown callers can still call and it's just a tad annoying. Basically useless to block people from calling when they can swtich their caller ID off. I'm using an iPhone btw.

Although some people tend to manipulate this service for their own selfish gain, it is of much help to those using it to protect their businesses. However great this service can be to your mobile phones, you need to know that, you should at not any one time use this service to do any wrong, or manipulate people by stealing someone, else's identity, as it is punishable in a court of law.
http://www.hidephonenumbers.com/
The only time you are allowed to use Caller Id Spoofing, is when you are not sure of the other end, or the person you are calling, and want to protect yourself from harassment from the same. These are the only times when you can use this service to call other people.

  • When you Block Caller on iPhone, does it completely block them or do they show up as Unknown? I routinely "Block Caller" telemarketers, so does using the iPhone "Block Caller" option block all calls, or will the calls still come through and just show up as "Unknown"? I've received a lot of "Unknown" phone calls lately, so that's what I was attributing it to.
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  • Unknown caller keeps calling? Me and my friend were prank calling In N Out and McDonalds but we didn't talk, we just made random funny noises and hung up. A couple minutes later I get a call titled "Unknown." I didn't answer. Yet all night that person tried calling me. Any advice? Am I in trouble? I'm using an iPhone 5 with iOS 7.
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