If there are specific domains that your organization would like to block from requesting access to your trust center, you can do so on the Trust Center settings page.
In your account header, click the Settings icon
In the Settings page menu, scroll to the Features section, select Customer Trust, and go to the Trust Center tab
Scroll to the bottom of the page
Select + Block Domain
Enter the domain you would like to block from requesting access to your Trust Center
Select Block
Keep in mind that this only pertains to restricted Trust Centers. If your trust center is public, anyone with the link can access what you have published.