CAPTCHA is an effective way of weeding-out automated traffic on websites
(Picture: TfL)There are few things more annoying online than constantly having to prove your own humanity by clicking on pictures of postboxes, buses, or (in the case of TfL’s more playful implementation) big cats.
This process is known as CAPTCHA and is a necessary evil. Without it, websites are vulnerable to fake traffic which is a waste of resources at best, and can become a structural weakness for them. This is a vital layer of protection against Distributed Denial of Service (DDoS) attacks — where malicious hackers send huge amounts of fake traffic to a website — which can take down big online sites with bots.
