Seriously a real fan never would sue a company... Maybe if he send it directly via mail and wanted money for it? Seriously taking that ideas can be predictions? If a company would be smart then they would hire fans with best and most ideas.Do I have to mention again how Sega and that one Star Trek writer got sued by doing that?
EDIT: Or almost got sued. I can't remember the details right now. Point is, you can't use fan ideas or you will end up in court.