A couple of days ago, some robots started to sign up on the website (about 30 in a couple of days), they don't do anything on the website (as I'm guessing they don't find what they're looking for).I'd rather not have a CAPTCHA on my sign up form, is there any risk to letting those robots signing up with the website?Is there anything I can do besides a CAPTCHA (they have different IPs, passwords, emails...)?
Robots signing up on website
spam;spam prevention;botattack
Look into having a honey pot in your form, this will only work though if it's a generic robot, as the moment a custom script is written the honeypot can easily be bypassed.Also, if you're not keen on a CAPTCHA you could try Solve Media's alternative and earn a bit on the side at the same time, I think it was Ticketmaster who recently started using them as an alternative.Something else I've seen to stop cURL automation is to set a cookie in the user's browser then using JavaScript and a combination of that cookie encrypt the _POST data, so that it's gibberish. This can be a real pain if you're working with cURL as you then have to reverse engineer it, again this slows people down, but does eradicate the use of bots if someone has enough time on their hands.Of course if they really want to get at you they can use Amazon Turk to pay a real human $0.01-$0.05 for each signup / action on your site.