Should there be any reason for a user's access to the Forum tool to be revoked, this is possible with the blocking functionality. When a blocked user attempts to open the Forum tool, they will be presented with an error, citing the reason that they were blocked.
Blocking a User
To block a user, their forum profile must first be viewed. This can be done by clicking on that user's name anywhere inside of the Forum tool (it will be shown against any post or thread made by them).
The upper-right corner of their forum profile contains a button labeled block user. When clicked, a section will be revealed containing a text field for the reason the user is being blocked, and two buttons. Once the reason has been entered, click the Block button, and that user will no longer be able to access the Forum.
Unblocking a User
Users that have been blocked can also be unblocked. This is done by first opening the Forum tool (found under Communication suite), clicking Admin Mode, Admin Tools, and then the Blocked Users button.
Here, you will see a table detailing all the users that have been blocked from using the Forum tool, the reason that was provided, and a button on the right-hand side to unblock the user. Simply click this button to return forum access to the user.