Protecting SWF from Hotlinking or Rehosting

I’ve made a game in flash that I want to upload onto my site but I don’t want it to be able to get hotlinked to or hosted from/on another site.

What would be a good way to prevent this?

I first thought of getting a varible from a text file and using an IF function on load to check if that var was loaded but that would only prevent Hosting.

I then tried putting the var in the html code for the swf but that don’t seem to work so well, when I refresh the page the movie randomly seems to play normally or goto my “this is stolen” screen.

Can anyone help or suggest something?

Thanks in advance to those that help.