A lot of accounts that sign up here are bots that get nuked pretty quickly.
How does the site get to know that if they are bot or real accounts?
And why doesn't the site use a better captcha like recaptcha?
You can understand if a new sign up a bot or not like that;
That's the member list ordered in latest registers;
https://bitcointalk.org/index.php?action=mlist;sort=registered;start=0;descAnd check the "Website" column, on the second page there's this user:
https://bitcointalk.org/index.php?action=profile;u=505845Website: "Dish tv recharge in Rawalpindi" that's the keyword bot's spamming backlink for a website.
One of those bots is scrapebox:
http://www.scrapebox.com/it can automatically sign up for forums and create accounts to provide backlinks.
It's not hard to understand if a new account bot or not.
Some of those bots are capable of opening threads like "Hi, I'm new here, that's my website check it". Those accounts can be reported (I've reported some of them) but if they just create an account and don't post we can not report it to be nuked