Sure. If you plan on implementing this as some sort of end-user device that would be hooked up to a phone handset or a software "app" you would install on a smart phone, then all you've got to work with is caller ID. Caller ID can be blocked by the caller (e.g., by dialing *67 first) and spoofed, including the purported outgoing number. In fact, VoIP systems like Skype have made spoofing caller ID and now even ANI, a toll network analog of caller ID, trivial.
So even if you keep some sort of constantly updated database of numbers used by robocallers, you are still relying on the robocallers 1) not blocking outgoing caller ID and 2) not spoofing the numbers of legitimate users resulting in them getting blacklisted.
So even if you keep some sort of constantly updated database of numbers used by robocallers, you are still relying on the robocallers 1) not blocking outgoing caller ID and 2) not spoofing the numbers of legitimate users resulting in them getting blacklisted.