you can simply input a "s" in the "http", so it will become https and the auto-embed will fail, like we see happens often here.
@Jorge
blip.tv isnt working when I asked you that, so maybe they changed something. I dont think its worth to pay for a upgrade since youtube still works and its protecting well the forum against embed spams. I asked it only to make things easier to everyone, when it involves money or a headache its better to let it be xD