Adult sites

Why can't I download videos from adult sites any more. I used to be able to download from all the adult sites and now they tell me it's not a video URL. but there are no mention of "embed" in the URL what so ever and I don't think xvidos or others have had time to embed every video on the site. There would be thousands. I just updated to the 4.2.1800 version and it still doesn't work. I am also running the Plus version.

Thanks

William Gray