We recommend the creation of a system that allows users to report, to an online database system, the originating telephone number of unwanted solicitations, advertisements or robotically placed calls (henceforth called 'spammers'). We also recommend that users' telephones or external hardware may automatically query the database about the telephone number of an incoming call (before the call is answered, or even before the telephone rings) to determine if the caller has been flagged as a spammer by other users, and optionally block the call or otherwise handle it differently from a non-spam call.
The recommended system thereby would provide a means whereby users can make reports of spam calls as well as ask if others have reported a caller as a spammer. While the first few people called would get spammed, after a sufficient number of reports are made, further calls would be blocked.
The recommended system would work on most types of telephonic platforms - smartphones, some feature phones, POTS lines, VoIP, PBX, and telephony providers - through the use of software and optional inline hardware. In addition to crowd-sourced blacklisting, we also recommend a means to whitelist specific numbers so that, for example, emergency calls will always go through.