Ah, cold callers, telephone spammers, telemarketers whatever you want to call them, theyre annoying. Frankly, its remarkable that companies still try the decades-old technique in this era, but I guess people still fall for the bait (or theyd stop doing it). Of course, the ability to block calls is also useful in more personal situations. Sure, you can block people on Twitter, Facebook, and all the other social networks, and you can send their emails straight to your Junk folder. But its also important to be able to stop people from contacting you by phone.