In a previous life, not too long ago I was involved in forensics and still teach. Uploading an attachement to Amazon etc shouldn't leave an IP adress. The software you created the document on could. For instance any Word document will have the software owner's name on it. It's my belief that the information is scrubbed during the formatting... but am not sure.
But, to answer your question... create the work on a clean computer that you put a fictitious name on and the same with the word processing software you write with. And then, upload from the library or some other Wii source that isn't associated with you.
Good luck with your © copyright!