I'm interrupted far too often by cold-callers, PPI spammers, or even just from people calling the wrong number. Last week my Out Of Hours support phone got an SMS from a hospital laboratory saying “your test result is normal”. I've been thinking about ways to reduce the number of nuisance calls without hampering the usability of phones too much.
I think part of the problem is that phone numbers are too short: we've run out of numbers. (When you get a new number, someone has likely had that number before you. Who knows what they were up to?) A more serious problem is that the numbers have no check sums. Mistype just one digit and you end up calling the wrong number. With a good check sum you could instead receive a helpful message saying that the number you typed contained an error, and in some cases could even tell you which digit was incorrect!
A more serious pest is the PPI spammers and many cold-callers that use an auto-dialler. They work by calling many people at a time and either play a recorded message or connect punters to an operator. I receive PPI spam several times a week now from multiple different numbers. Some even call from overseas!
Dealing with short numbers should be simple. Their length has been extended many times before. (Many years ago, the local shop where I grew up had phone number 11.) The problem is they don't go far enough: I don't see why we can't just double the length of phone numbers. (Nobody actually memorise phone numbers these days, do they? If so, this could be an incentive you to kick that habit. Or, make it actually impressive. Either way, it's a win.) Obviously we could retain the current numbers for anyone that would like to put their number in adverts, leaflets, etc. Doubling the length of phone numbers could help combat auto-diallers, in that it would become much, much more resource intensive to simply try guessing numbers. Phone companies could also charge a small fee for connecting you to a number that doesn't exist, to further deter auto-dialling.
While longer numbers would mean not having to use a recycled number, and making auto-dialling impractical, it is not enough. It offers no protection from people giving or selling your number to people you don't want to talk to. We know that blacklisting doesn't work: like me I'm sure you block every cold-caller you encounter, but every week they're using new numbers. We cannot block them in advance. Or can we?
This is where white-listing comes in. Apple's iPhones have a feature called DND (Do Not Disturb), which allows you to specify a time range when your phone should not make a noise when receiving calls or messages, so you can avoid being woken up in the middle of the night for example. More interestingly, they allow you to specify that some people in your contacts can get through to you, even if DND is on. I'm close to turning my phone on DND permanently, but allowing access from family and friends in my contacts. Although, you would then still see missed calls, so if that annoys you (it does me) it's not a complete solution either.
PS: I've found out that Windows phones allow you to block callers with no caller id. This is something that I've wanted for a long time. Hopefully Apple will implement this as well. Or maybe I'll be buying a Windows phone next…?