Michelle Dallacroce was hopping mad when she received a letter from Mothers Against Drunk Driving demanding she change the name of her organization, Mothers Against Illegal Aliens. "I couldn't believe it," Mrs. Dallacroce said. "I don't know who would be confused by this. We don't even have the same acronym." Mrs. Dallacroce, president of the Phoenix-based advocacy group, received a certified letter Oct. 10 stating that MADD owns the rights to the name "Mothers Against" and giving her 10 days to stop using it. "While we do not oppose the name of your organization as a whole, we cannot permit...