Yes, one you get to needing a fake passport, or other equally stringent ID, from a list of authorized countries, the price per spam bot will basically be too high for any viable commercial spam.

This might actually be a pretty enjoyable experience for a lot of users. If every user can be assured that every communciation is actually from a real person, or a real organization that can be sued, or at least a fake personality that someone put tens of thousands of dollars behind.