You can easily encode mailto and plain email address links on your WordPress site and hide them from spambots. Email Encoder Bundle is a free WordPress plugin that plugin works directly when activated. Simply install and activate it, after activation visit your admin area Dashboard -> Settings -> Email Encoder Bundle plugin option page and check where you want options to take effect like you can enable it on all posts, comments and text widgets. You can set it to automatically encode both mailto and plain email addresses links, you can set class for mailto links and there are few more useful options.
With WP Mailto Links plugin you can easily protect all email addresses and mailto links from spambots and being used for spamming. The plugin is easy to use and configure.
It is possible to show-hide categories based on your WordPress site user roles. The CaPa Protect is a free WordPress plugin lets allows you to hide or display categories based on user roles types like Editor, Author, Contributor etc. The plugin also provides you the feature of showing a message whenever a someone arrives without permission on a protected blog post of your website. Also you can simply hide everything and your user will not be able to know the existence of hidden post.
Make all your BuddyPress powered community private. You can select which pages you want to exclude from protection so that only selected pages come visible to logged out users. For example: If you run a blog within your BuddyPress site then keeping only your blog public and other things private is possible or you want to make only registration and home pages public so that people can come in and join your site without seeing what is happening there inside.
Here is an easy way for protecting your WordPress site’s email addresses from email-harvesting robots by encoding them into decimal and hexadecimal entities.