Unfortunately, if this succeeds, you'll need to figure out a way to prevent (or mitigate) spam and other abuse. It's an awful problem, and I'm not sure if there

Unfortunately, if this succeeds, you'll need to figure out a way to prevent (or mitigate) spam and other abuse. It's an awful problem, and I'm not sure if there's any way to really deal with it. A PGP-style web-of-trust might work, but that has its own downsides.