 Taco Bell has petitioned to cancel two trademarks by rival restaurants. The trademark for Taco Tuesday, one is a restaurant known as Gregory's in New Jersey, and the other is Taco John's, claiming that this phrase has become a common phrase of the English language and should no longer be entitled to trademark protection because it doesn't identify a particular source. This is a wake up call for trademark holders that if you have rights to a trademark, you need to enforce them or they could be seen as becoming generic.