Is there a way to automatically have a copyright attribute when content is submitted?
The only ready-made solution I know of is Plagiarism Checker - Authentication Framework.


  The module is a framework which supports various search APIs (plugins) to scour the net looking for possible plagiarized content. The framework provides support for 2 different types of APIs - Standard APIs (Google and Yahoo plugins are included here) and Custom APIs (such as the 3rd party paid authentication service from iThenticate (www.ithenticate.com)).


Note that these APIs are either not designed to plagiarism discovery, giving a lot of false positives, or may be paid. Also, low usage count and Development status: Maintenance fixes only should make you careful.