They are not preventing hotlinking with rtmp. When a site allow users to embed video, it is always possible to hotlink.

Next version will have support for lighttpd, we already have it done on

http://video.bizhat.com/view/723/nice-parking/

The video url will expire after specified time. This is is only possible on dedicated or vps, not on shared.

On shared, we will try some php based script to prevent hotlinking.