[dragonwriter]

> I've noticed that almost all of the robocalls i receive come from a number beginning with the same three numbers as my number. I would love for the ability to block all calls beginning with these three numbers, UNLESS they are already on my contacts list.

This will become unhelpful as soon as it becomes sufficiently popular (perhaps even before: as the trick gets more widely recognized for what it is, the mental spam filters it hacks around will get updated whether or not they are augmented with technological tools, and the practice will lose its value and be abandoned, making automated filtering that assumes it is widely used more likely to screen out good calls than spam.)