Why Don't Cell Phones Block Calls from User-Defined Numbers??
 

Well, why not?? Just like how e-mail has spam filters, why can't phones, which run on computers, do the same???

Is there some kind of First Amendment issue here? Can't imagine that such a feature (at least the second-most wanted functionality, I'm sure) is technologically difficult to implement....

I think it depends on the service provider. Here in Egypt, on one of my providers (Vodafone), I can 'screen' a number. The phone still rings but I can't hear it. Texts, however, are filtered off for review in a separate part of the message storage system. On my Etisalat phone service, I can only block all or none, not just one number.

Smart Phon Apps Do
 

Some iPhone and Droid apps do exactly that. I just forgot the name. Search for call screening apps. Some will go as far as not let YOU call that number also, like if you didn't want to call an ex after a night of drinking ;p

I think my Android 2.x phone has this feature implement directly without the need for any third party app.

TELCO Also
 

And you know, even before apps and smartphones, I'm pretty sure that you could notify the telephone company and block certain numbers from calling you. Phone networks are run off big computers called PBX's which have call routing tables that are very programmable. It's definitely possible.

Did you find a solution?

Take care,
Chad.

Thanks for the replies, smart people! Food for thought as always....

I did contact T-Mobile but they claim they can't prevent numbers from calling me. I just hate getting those robocalls and other spamsters even though I'm on the National Do-Not-Call Registry (landline and cellular -- yes, you need to specify both separately).

I'll look into the Android thing...my Samsung runs (fitfully) on Android something-or-other....

Thanks again everyone! I feel hopeful now. :)