NBC and the Major Sixth

In one of our marketing chapters we discussed trademarks, copywrites, and pattents. It was brought to our attention in class that anything by a company can be used such as their name, logo, a short snippet of music, or in NBC's case a interval of music. NBC has been using the interval of a Major 6th for decades which in solfege for musicians is going from do to la back down to do. Copywriting or trademarking this interval seems very silly since this interval has been used in pieces of music for centuries. For at least 1400 until present this interval has been used. The interval would have been seen and used in compositions hundreds of times. NBC must be careful in trying to copywrite this item because it so obviously used in the musical langauage all the time. It would be like copywriting the letter "I" which cannot be done. It is argued that the interval of a Major Sixth is only copywrited by them on the pitches while singing N-B-C but it still shows the silliness of copywriting something that is so readily used.

Is there any other case or instance that something you know is copywrited or trademarked that seems silly or stupid which people may use day to day or every day?