I disliked his videos and wrote negative comments (and mention the link to your channel).
I found 4 stolen videos where I put a negative comment:
https://www.youtube.com/watch?v=MoLk0aentCI
https://www.youtube.com/watch?v=MUW7LfEkXeM
https://www.youtube.com/watch?v=P1AaTu-4xt4
https://www.youtube.com/watch?v=u01CxFDIDDE