Google captchas while using Caltech Wireless

Recently, users on the Caltech wireless networks have had Google searches interrupted by a "captcha", which Google uses to prevent automated software programs from abusing Google's services. Caltech's wireless networks use Network Address Translation (NAT) to conserve public IP addresses, which can trigger Google's detection mechanism, since multiple computers will share one IP address. Encountering a captcha while using Caltech wireless networks does not necessarily indicate that anything is wrong with a user's computer. This is simply a change that Google has made to attempt to verify that a human is accessing their services.