I'd say that you should take their advice. Write the letters. Go out to anime conventions and ask for signatures. If you do it right, you should get hundreds, if not thousands. Fanime Con in San Jose is looking for fan panels. Why not suggest doing one on this topic (or sneak it in to another if it's not permitted). Heck, talk to the reps that will be at the con. Online stuff doesn't count for much as it's easy to sign a website petition, but a lot of work to do it in person.