I once wished for an algo to predict a person's religion from their name and email to ascertain whether it was appropriate to send them a Diwali Greeting. https://gtm360.com/blog/2014/01/24/how-a-small-problem-in-mail-merge-leads-to-a-big-lesson-about-content-marketing/. I never dreamt that it was so damn hard to just predict gender. On a side note, this tool claims to predict gender from email addresses and usernames. All examples that have busted the tool have words like stupid, women, etc. TBH, while whatever has happened to this tool has happened, I can't think of any email addresses or usernames with these words. In other words, I find these tests dubious. Twitter works like Twitter but no rigorous testing methodology for this tool will use such test cases.