If someone else uploaded a video that's the same as mine but has added a bit of text to it and added some stuff on the end, will youtube recognize that the part that's mine is mine and will cancel that youtubers account for using my video in his video with a few additions?
Youtube has a page setup so you can file a copyright infringement claim on the other video. Here is a link to the page - http://www.youtube.com/t/dmca_policy If you think is might be an ongoing problem, use this Content Verification Program page. What that does, it will scan videos for certain content before they are published. http://www.youtube.com/t/copyright_program Videos that are flagged with the Content Verification Program are disabled. The person that posted the video is then sent a message that the video has been flagged and made private. They then have the chance to file a reply saying that the video does not violate copyright, or they have permission to use the video.
Kev gives you the best advice. I had a similar issue and filed a claim. It took a while but eventually they deleted the duplicate video.
yeah my preview movie in youtube was flagged too and youtube said i resume there after like june 4. someone flagged my video that it has this adult content though it was just a preview. but if they added some stuff to it and uploaded it then probably its their own video now.