The HotLink system allows you to protect site files from being used on other resources by embedding links to these files directly into the page code and other things.
HotLink settings are managed in the section "Hosting → My sites → HotLink - file protection»:
To protect your files from direct links from third-party sites, specify the desired settings and click "Save»:
example.com/files/images/
- allows embedding only at a specific address of a specific domain.*.example.com
- allows embedding for all subdomains of the domain example.com
.example.*
- allows embedding for named domains example
any zones.example.com
will be displayed, but when prompted for example.com/image.jpg
access will be denied.