Like so many I've had an ongoing problem with spammers. So I installed smartcaptcha. It really works. But there are a couple of things you should know. I found out the hard way so I hope this posting will save you some trouble. I run portdefender.net. Our forum is for members and the general public interested in VPN's.
I spent a couple of days getting smartcaptcha to work. The first problem I had was that smartcaptcha requires Anti Brute Force. After installing that I still couldn't create a new member. After a lot of fruitless effort I finally realized that the browser I was using had cookies turned off. Once I turned on cookies it worked perfectly. I hope you find this posting helpful.