I've been getting calls off unknown numbers?

On my iPhone 4 I've recently been getting calls from a private number. Every time it rings, it says "Unknown Caller" and it's really annoying! How do I block these unknown calls? I've heard there's a way to stop you from getting "Unknown Calls" but I don't know how to do it and if anyone knows I'd be so thankful if you told me! I really need it to stop!

Can I sell my iPhone? Is it unlocked now?

A few months ago I finally upgraded to an iPhone5s and now I just have my old iPhone4 sitting in my drawers and I want to sell it. Is it unlocked now that I have a new phone? I have Sprint as my service.

Found an locked iPhone, how to use it?

Ok so my dad works for the train station and he found an iPhone 4s and after 30 days if no one came for it, he could keep it. Before you say give it back to the owner, it's too late. So I restored it and it's set up like an regular new iPhone but when I try to activate it I need the person's iTunes account to activate the phone. Is there a way to still use it without the account? So I can just use it as an iPod touch?

Added (1). Also they did try to find the owner, nobody came looking for it. This is how all train station workers are set up.

How to preload a Netflix tv show to an iphone?

I have a 2 hour flight and want to watch some tv shows from my netflix account but since Netflix uses a lot at phone data I need to preload it while I have Wi-Fi so is there a way to preload 2-3 episodes to my iphone

Would I be able to pull of an undercut?

I want to get an undercut like this… Not the color just the cut
Would I be able to pull of an undercut - 1

this is me
http://psychings.tumblr.com/tagged/iphone
http://psychings.tumblr.com/tagged/wc