CAPTCHA’s are an irritating but necessary evil. The system that is used to verify whether or not a user is human has been around a while and it had to evolve because machines were getting better at reading the text than humans.
Google acquired reCaptcha back in 2009. It updated the system in 2013 to allow for the ubiquitous “I’m not a robot” checkbox that’s all over the internet. That version worked by determining the user’s humanity through their clicking style. If the click seemed fishy, a more elaborate test would be offered. But the Invisible CAPTCHA is able to recognize that a user is not a bot simply by analyzing their browsing behavior.
When the search giant initially bought reCaptcha it was actually for the purpose of integrating it into its giant book scanning project. The technology was great for digitizing books that were illegible to Google’s transcription system. But its unclear what Google gains by continuing to improve the software.
But don’t count out the possibility that Google is improving its machine learning capabilities through your behaviors. And Ghosemajumder points out that Google knows about the past behavior of users when they’re logged in, which would make the system more accurate. That could be a small incentive for some people to ensure they log in.