In some Greg Egan book (Permutation City?) there are AI spam bots (that call you with full video and try to impersonate someone you know, then advertise a produ

In some Greg Egan book (Permutation City?) there are AI spam bots (that call you with full video and try to impersonate someone you know, then advertise a product) and AI anti-spam bots that take your calls and hold a conversation while trying to figure out if the caller is real. The anti-spam bots are at a disadvantage because at some point in the arms race you have to make the bots actually fully intelligent, and then exposing them to spam 24/7 is torture and illegal. Spammers don't care about legal issues.