In the case of trademarks, if it's a valid complaint (and this one clearly isn't) and you choose not to prosecute, you have a weaker case the next time. So if

In the case of trademarks, if it's a valid complaint (and this one clearly isn't) and you choose not to prosecute, you have a weaker case the next time. So if McDonalds sees someone open up a McDonny's with similar menu items, they have to go after the trademark infringement. Otherwise they have no case when Burger King pulls the same stunt.