we’ve had some problems with reCAPTCHA in the last weeks, what brought me to think about reCAPTCHAS (again).
The last time I had a look into it there were concerns about the inaccessibility of CAPTCHAs in general. The latest draft of the Inaccessibility of CAPTCHA document of the W3C states that accessibility is still an issue. A comment raises concerns about privacy, especially in regards to reCAPTCHA as a service provided by Google.
Another concern that came to my mind is that Google Services are not accessible from every country (like the People’s Republic of China). So no users from those countries will be able to register as user by themselves.
So I wanted to ask if anyone knows other solutions to stop spam users for OJS. Are there other CAPTCHA solution that could be used right now?