Generally, the point of a CAPTCHA is to prevent automated use of a service. If we get to the point where CAPTCHA&#x27;s no longer work in preventing automated access to services, we need to look for atypical use of services.<p>For example, if a computer passes a CAPTCHA in order to use gmail to automate the sending of spam emails, look for users that mass-spam; typical users won&#x27;t do that. On the other hand, the computer may try to approximate the usage of a typical user to avoid detection. But if you cant distinguish automated use of your service from typical use of your service, then at that point maybe it doesn&#x27;t matter so much.