There has to be some not-yet-discovered way to have a capcha that is easy for any human but impossible for robot. Too bad capchas hurt user experience no matter how easy they are.
Another solution I came up with while reading HN comments: whitelist IPs instead blacklisting. Give access to well-behaving hosts/groups. It can even be shared across different sites. Although this would create a market for selling "good IP" proxies.
Another solution I came up with while reading HN comments: whitelist IPs instead blacklisting. Give access to well-behaving hosts/groups. It can even be shared across different sites. Although this would create a market for selling "good IP" proxies.