You need to relax. ContentID doesn't always know that you have the rights to use a particular song. All it is doing is matching that song to the group that manages the license. You dispute the claim stating you have an open license to use that content per partnership with Fullscreen and then you move on with your life. Running to a forum to freak the f**k out, instead of calmly handling it won't get you anywhere. The Content Match Dispute Process is precisely where you tell YouTube and the content Owner that your channel is one that has the rights to use that content. It is not some vindictive person seeking out channels to try to hurt.