I'm currently under contract to proofread a manuscript at a fixed price. After about 1.5 hours of work, I encountered some suspicious wording, only to discover that the manuscript blatantly copied and pasted from an online article without crediting or citing at all. Not only is this highly unethical, but it is illegal. What should I do? I could just terminate the contract, but I'd be more than a little annoyed that I've already spent this much time on it (though there's probably nothing to be done about this). I also feel like I should bring this to someone's attention, since this manuscript has been taken on by a publisher. What should I do?