Re: We need a secure caller display system
If I knew anything about phreaking, and assuming such a thing is even possible, I'd build a gadget that forces the POTS network to give up the CLI regardless of the caller's intent (surely the network operator must have this information, otherwise it wouldn't be able to connect the call). No more "INTERNATIONAL", "UNKNOWN", "OUT OF AREA", "WITHHELD" or any other bullshit.
I'd also find a way of obtaining the customer database of all "presentation numbers" and match them back to the real subscriber number, along with a reverse lookup table of all other numbers and their associated customer details, so that the Caller Display would not only show the real number calling, but also a company/personal name, and extension number if applicable (yes, the latter would also involve hacking every PBX in the world).
It's pure fantasy, of course, but it's #1 on my telecoms fantasy hack list.
As to why ... if someone is calling me, not by accident, then they know my name, telephone number, and probably a great deal more. As a matter of principle I therefore demand the right to know at least as much about them as they know about me, before I decide whether or not to accept their call.
I really don't think that's an unreasonable expectation.
As a bonus for my fantasy hack list, I'd like some means of automatically hacking in to any offending autodialers, and even human operated telemarketing systems, that assault my phone, and utterly brick them somehow, whilst identifying the company directors by name, then hacking all their personal records and transforming them into personae non gratae that will never again be able to even hold a bank account, let alone operate a company.