You can block someone from your profile page or the page showing all your followers. By taking this action, this means you and that person cannot interact with each other through any of the community features we have (Groups, Chapter Comments, Wall, Reviews). Please keep in mind that you will each still have access to each other's stories but none of the interactive components.
You'll be able to see a list of everyone you have blocked by either going to your settings page on the website OR by going to My Profile on the app and then selecting Edit and scrolling down to the bottom.
If you want to unblock someone, you can also do that from your profile page or the page showing all your followers.