A few years ago there was a clothes detergent (I think) called Microsoft. Not even a moron in a hurry could have mistaken this detergent for a product made by M$ but they were told to change the name or face a lawsuit.
Similarly, a former IBM employee set himself up in business selling wine. He used the trading name Big Blue and was taken to court by his former employers. They searched through their catalogue, desperate to find a product containing the phrase "big blue" and eventually found a typewriter ribbon!