Is it possible to prevent users from using the "break link" option for an object within data module that links to another data module. We'd like to use linked modules to implement data security and prevent users from circumventing this by breaking the links to the source then changing the linked module however they like.

When a data module has links to other data modules there is an option from the context menu (ellipses) that allows the user to "break links". Breaking the link enables the original source data source thus circumventing any custom transformation or other business logic that we have established for the users to consume within the linked data module.

I've read blog posts that indicate this can be achieved via security or capabilities but so far I have not found which option disables this ability within the data module.

blog source link: http://ibmblueview.com/data-modules-as-a-single-source-of-truth/

I've accomplished this by defining Cognos roles specifically to set the UI customizations.

Accounts -> Cognos -> navigate to your role -> Customization -> Features -> Data Modules -> Context Menus -> Shaping options -> Uncheck Break Link.

The UI customizations here are not additive, so the highest priority group the user is part of controls which UI elements are visible. I recommend defining a group for each type of user you have and only using those groups to define UI customizations.