The US Supreme Court hears arguments today from the NFL and apparel-maker American Needle, which sued the league after it went all-Reebok a few years ago. Anti-trust law is at the center of the case. Is the NFL one giant business, or a group of 32 competing companies? If the court sides with the NFL, the decision could ripple through all pro sports, limiting competitiveness in free-agency, tickets pricing and merchandise. An appeals court has already ruled in favor of the NFL, and the price of official NFL hats has skyrocketed. But the NFL wants to cement it’s position with a supreme court ruling. Critics say that kind of precedent could drop player salaries and make it more expensive for fans.