there are 2 different hacks
1 PPl are unable to right-click to any media files in ur forum. It happens like u try Right-click on any youtube videos
2 Ppl are unable to do right-click. They can go to " properties". However, the URL dont show the location of the files. So ppl can't steal that files.
For example, normally, 2 years ago, it will be
www.yourdomain.com/forum/music.mp3
Now ppl can hide it.. It becomes...
www.yourdomain.com/asdfasdfasdfsda/asdfasd (something else to prevent stealing)