When a username is hidden in the results list in Special:CheckUser, the CheckUser summary table treats the text that is shown instead of the username (i.e. username removed) as a valid username and therefore provides a wikitext link for it.

Example:

Steps to replicate the issue

1. Create a new user account
2. Login to a user account with the suppressor and sysop group
3. Block the user with hideuser enabled
4. Login to an account which does not have the suppressor group
5. Run Special:CheckUser where the target of the check the IP used by the user you blocked in step 3

What happens?:
The CheckUser summary table (the one shown in underneath See results in a table) has a row for username removed where the text is clickable.

What should have happened instead?:
The row should be there, but it should not have a link to avoid confusion.