Well if it makes you feel safer then that's great but personally I don't think anyone that will want to nick a camera will go shopping for a particular model or brand, they will see a camera and that would be enough.
Then again I suppose it is embarrasing owning a Nikon
Maybe you can get some Canon stickers to hide your embarrasment
Seriously though just a bit of good old Nikon/Canon banta which is traditional in these parts.
I do think you have hit on a very serious point and have to say I do feel a little wary when I go out at night with my DSLR and people can sometimes get funny as they assume you are trying to take shots of them especially when the have a bit of booze on board.