In 2007, New York City applied for trademark protection with the United States Patent and Trademark office for a logo that consists of an apple with a stem and leaf. In 2008, Apple, Inc. filed an opposition to that application claiming that there would be a likelihood of confusion among consumers with Apple's products and services.
The two parties have since reached an agreement and the opposition proceeding was terminated. A Notice of Allowance was subsequently issued to the city of New York allowing them to use the logo.
Apple, Inc. is a good example of a company that actively and consistently polices their mark to prevent any aspect of the mark from entering the public domain. However, this case also shows that Apple, Inc. does not own rights to every drawing of an apple!