With the YouTube Content ID manager you can claim or take down anyone who had upload your video onto their own channel. Today I found this person under the username Betty G. Jeans downloaded every films on my channel and uploaded to his/her channel. Maybe a newbie, the user removed all when realized most probably he/she won't be able to monetize any of it and eventually the channel was terminated by YouTube. I take it as a compliment that our films got audiences...