Which team is known historically as the "Monsters of the Midway"?

What was the nickname of the Seattle Seahawks' secondary in the 2010s? What was the nickname of the Dallas Cowboys' defense in the 1960s and 1970s? What was the nickname of the Denver Broncos' 1970s defense? What was the nickname of the Miami Dolphins' defense in their 1972 perfect season? Which team has long been nicknamed "America's Team"? What are fans of the Green Bay Packers commonly called? What yellow item do Pittsburgh Steelers fans famously wave? What is the name of the famous fan section at Cleveland Browns games?