You're right, of course, but I think that if McDonalds let others use them, they'd have a good chance of becoming well-known within a generation, just like some

You're right, of course, but I think that if McDonalds let others use them, they'd have a good chance of becoming well-known within a generation, just like some of the old VCR icons are today due to use in myriad music players, video players, etc.