Not quite true.
In most cases, you must have written permission from the NFL to show the Super Bowl on any screen greater than 55 inches or when the audio is played by more than 6 speakers. But government regulations give a special break for Super Bowl viewing in private residences.
The US Copyright Code Title 17, Chapter 1, Section 110, "Limitations on exclusive rights: exemption of certain performances and displays," allows in-home viewing as long as you comply with the following:
- You may not charge your guests (although you can ask them to bring food and drink or kick in a few bucks for snacks).
- The TV must be inside your home. If you invite the neighbors over and use a projector to watch the game on the side of your house, it would be considered a public viewing and you would need to get advanced written permission from the NFL. (Mass out-of-home viewing of the Super Bowl is only legal at “sports bars and other businesses that televise sports as part of their everyday operations.”)
Just be glad that the government lets you watch the Super Bowl at all...