Protecting your site from spammers does not have to be scary or difficult. Without protection your site could be overrun by automated spam bots trying to sell fake products angering your members. Since these accounts can make up 98% of all attempted registrations you need to have a game plan to deal with them.
The first line of defense is the user activation email sent during registration. However, many sophisticated spammers can automate the click of the activation link. This also doesn’t stop human spammers.
The internet standard to combat spam is Google reCaptcha. It has several options including to be hidden, checkbox only or complex image recognition. Don’t we all know how difficult it is to pass the complex image captchas even as a human?
If you want to make certain no spammers sign up for your site you can require a site admin to approve each new registration request. At the time of writing, we think BuddyPress Registration Options is the best plugin for most users. This plugin will prevent any non-approved member from posting anything to your site until approved by an admin. This is easy to manage with a small community but with a large community you would need to delegate help to approve requests or install a different plugin to help weed out spam accounts.
At the time of writing several previously well known plugins are now deprecated including WangGuard. We think Advanced noCaptcha & invisible Captcha is best for most users. It is translated into many different languages and provides more captcha options than any other plugin.
The war against spammers will never end. How you manage to deal with them may change with time, as solutions stop working and plugins come out with more advanced techniques. We recommend doing your research and searching the WordPress repository for the best plugins for your site.