The best way to deal with it? Ignore it, or be amused by it. If you post your videos anywhere on the internet, you open yourself up for these sorts of things. You can do all sorts of stuff to "prove" that it's yours, but they will still argue against it. I used to try to get people to credit me when I found my videos elsewhere, but after awhile I just sort of gave up. However, I do follow the video, check for comments, reply to questions (because inevitably someone will ask something and stump the poster like "What program did you use to make this?") and that sort of thing.
On a related note, I've noticed a lot of stealing of online handles to try and authenticate the videos uploaded to the tube. Usually spelled wrong, they make entire accounts and transfer our info from the org to their tube account so that it's harder to point out the fake.
http://youtube.com/profile?user=Koopeskiva
http://youtube.com/profile?user=IlleiaAMV
So these ones not only take credit for our videos, but credit for BEING us. That's a little bit disconcerting.
If so, how did you deal with them?
