A Large-Scale Real-World User Study of reCAPTCHAv2 finds 819 million hrs of human time has been spent on reCAPTCHA in 13 yrs
A Large-Scale Real-World User Study of reCAPTCHAv2 finds 819 million hrs of human time has been spent on reCAPTCHA in 13 yrs
Since about 2003, captchas have been widely used as a barrier against bots, while simultaneously annoying great multitudes of users worldwide. As their use grew, techniques to defeat or bypass captchas kept improving, while captchas themselves evolved in terms of sophistication and diversity, becomi...

From the article:
“In terms of cost, we estimate that – during over 13 years of its deployment – 819 million hours of human time has been spent on reCAPTCHA, which corresponds to at least $6.1 billion USD in wages. Traffic resulting from reCAPTCHA consumed 134 Petabytes of bandwidth, which translates into about 7.5 million kWhs of energy, corresponding to 7.5 million pounds of CO₂. In addition, Google has potentially profited $888 billion USD from cookies and $8.75-32.3 billion USD per each sale of their total labeled data set.”
This means when a CAPTCHA serves as a barrier between people and an essential public transaction, people are being forced into involuntary uncompensated servitude. I believe this is a human rights issue.