Google promotes its reCAPTCHA service as a security mechanism for websites, but researchers affiliated with the University of California, Irvine, argue it's harvesting information while extracting human labor worth billions.…Forget security – Google's reCAPTCHA v2 is exploiting users for profit
In a paper [PDF]
https://arxiv.org/pdf/2311.10911
titled "Dazed & Confused: A Large-Scale Real-World User Study of reCAPTCHAv2,"
authors Andrew Searles, Renascence Tarafder Prapty, and Gene Tsudik argue that the service should be abandoned because it's disliked by users, costly in terms of time and datacenter resources, and vulnerable to bots – contrary to its intended purpose.
More here:
Web puzzles don't protect against bots, but humans have spent 819 million unpaid hours solving them
https://www.theregister.com/2024/07/24/googles_recaptchav2_labor/
"The conclusion can be extended that the true purpose of reCAPTCHA v2 is a free image-labeling labor and tracking cookie farm for advertising and data profit masquerading as a security service," the paper declares.