"Dianetics"

Certainly, one can trademark a word and have certain protections based on that trademark, but if I had written a book called The Dianetics of the Hunt in Ancient Greece prior to Mr Hubbard's little experiment with the gullibility of the human race, I don't see that that title would in any way be copyrightable.

I was always a fan of Johnny, so I believe his umbrage was righteous

There's an implicit minor premise here that I would love to see made explicit. Just to see what it is, mind.

Edit: Thinking about this, I believe it's a major premise that was left out. De maximis non curat vbq?

McDonald's, on the other hand, reigns unchallenged over anything beginning with "Mc"

I seem to remember McDonald's suing a Danish street vendor of hot dogs for using the name Macallans in his business name. He meant it as an homage to his favorite single malt but Mickey D sued and lost as I remember. Anyone know for sure?