Telecom Regulatory Authority of India, according to this post, is promising an Indian Do Not Call registry for Mobile Phones.
DNC registry in USA did make difference in number of calls received by average home owner, if you register. Now, the registration process is simple in US, where one can go to the federal government website and register the number on which they do not want to receive telemarketing calls. If the people do not have access to Internet, they can call a toll-free number. The problem is how to know that toll-free number. When you go buy a service, the provider does not tell you about that number proactively. I like the TRAI approach that you just tell the service provider and they will have to take care of it. I also like the fact that one can ask for blanket ban or selective service bans.
I think the mobile telephone carriers can implement such a service, where the end subscribers can list the types of telemarket calls they want. That would be positive call list. Of course the operators would do other way round, where they would implement negative call lists and then justify any calls received as not in the one of the blocked categories.
We also need similar service for SMS, where no unsolicited SMS can be sent. Lets call it DNS (Do Not SMS, not Domain Name System).
However, at the end of the day, this problem can not be solved, unless the call screening is in the phone itself, where the end subscriber somehow can see all the details of the caller (name, company name, address, what service does that company provide, how much would that call will cost me etc.). But, that might not be practical.
