when I login the trader platform with my smartphone, I get captcha's before I can login and I find it difficult to answer them because on the pictures the things are small and hard to recognize. Then I zoom in and accidentally press the wrong image. I have to keep zooming in and out to get those answered. Then I sometimes need several attempts to login.
Audio is hard for me to understand and is not an alternative for me. I wonder why captchas are used on smartphones (Android 7, Firefox), but not on the desktop browser?