It was pointed out to me that it is the obligation of the copyright holder to enforce their claim. Due to the nature of automatic copyright protection, it is up to the owner to decide what they believe is infringement and enforce it. As I understand it (in the real world) I cannot pursue "copyright" infringement on behalf of another person or entity unless they assign me that right.
When I come across images that may be copyrighted or found elsewhere I focus on the 'plagiarism' aspect of the problem. Many times this is enough of a reason for the community to remove (flag or unvote) the payout from a post.
If you are the creator of something that has been used without permission please report it. If someone is taking credit for someone else's work found elsewhere on the web, please report that too.
That is correct it is up to the copyright owner to pursue legal action or send a Notice, sadly the don't always know it's happening. Which is why I'm asking people to not vote on posts like that.
I really hope more users like yourself will spread awareness on responsible voting.
It is depressing to start my evening to find new users with accounts less than a day old with several posts of nothing but stolen content. It's even more depressing to see $$$ votes.