And not only "Mac" Apple's, also the other Apple from the UK that owns the Beatles rights. Buy this and you potentially have 2 lawsuits on your ass.
So,You mean to say no one have the right for the word apple. If we spell the word then we need to pay fine or go to prison.
I don't think prison is an option but a fine is on the cards if you infringe copyright. http://en.wikipedia.org/wiki/Copyright
for example if someone register the word appletunes in a country like India and other person registers the same name in USA then who will have the right for that word.