I'm not a lawyer, but in general, I think the answer is no. The DMCA protects online service providers from being liable for things their users do. Additionally

I'm not a lawyer, but in general, I think the answer is no. The DMCA protects online service providers from being liable for things their users do. Additionally, plagiarism itself is not crime or legal offense; instead you'd be most likely looking at some sort of copyright violation. It sounds like you have a specific situation and you're looking to sue someone, in which case more information about the issue you're having would be helpful.