I love Twilio, but every time I get a robocall to my cell phone selling me cheap insurance, I cringe a little, and wonder if Twilio is enabling this. I wish Twilio had a "is this a Twilio phone number" lookup so that I can report such activity.
Apple could provide this quite easily, and it would be a huge differentiator.
Then I remember that call centers probably rack up huge phone bills...
edit: replying to comment below, many countries have working opt out lists.
Of course, sometimes I get calls from actual humans for polls or advertising a product, but it's much less of a bother since it happens less often and you can reject them.
My phone should be saying to itself "Hold on a second, am I about to turn on the buzzer and display the text "Unknown caller" to the users? /dev/null it."
Maybe people don't know how to select this feature when they make calls? At least in GSM based networks you can select it on a per call basis when dialing (#31# prefix).
Eg. calling in anonymous tips to your local newspaper, communicating with an annoying company you don't want calling back, etc.
http://en.wikipedia.org/wiki/Mobile_phone_spam#Countermeasur...
Works with AT&T, Verizon, Sprint and T-mobile according to Wikipedia.
No-one knows about it of course, a recent survey found just 3% of people knew it existed or that the ICO were the right people to report these spam messages to.