Captcha.eu

Hardens and protects your site by locking down login, REST API, XML‑RPC, file editor, and applying HTTP security headers.

The DMCA Protection plugin for WordPress lets you install protection badges on your site in order to deter content thieves and protect your content

Prevent bots from creating accounts by blacklisting domains and usernames and present people with a human friendly security question.

Simple IP Ban is a lightweight ip / user agent ban plugin.

Protect your content with passwords using easy-to-use shortcodes. Supports both global protection and partial content protection.

Simple copyright protection for your images and text. No right click, no text selections, no screenshots. A very lean and clean plugin.