Cool, it reminds me of Sphinx Chat. The best antispam function was the price per message + bail amount that was lock for a certain period and return if message was not flag as spam after x hours.

We should have the same for phone call, unknow number want to call me? It will cost 10 bucks but fully refund if I approve the call as legitimate after ending it. You spam me, I keep the 10 bucks.