Of the many possible infractions players in the National Football League might commit, from roughing the kicker to celebrating too ostentatiously after scoring a touchdown, one they don't have to worry about is face guarding, deliberately blocking the vision of a pass receiver. There is no prohibition against face guarding in the NFL.
2007 AFC Championship -- Oops
Some NFL fans may be under the misapprehension that face guarding is an offense, particularly if they were watching the AFC Championship game in January 2007, when New England Patriots cornerback Ellis Hobbs was penalized for pass interference against Indianapolis Colt Reggie Wayne. TV broadcaster Phil Simms announced that it was for face guarding and added, "Easy call." The penalty was a crucial one, and, "To this day, there are fans in New England and Indianapolis who will say Hobbs was called for face guarding," notes author Sean Glennon.
High School Is Different
Face guarding is not a penalty in college football either, because the NCAA, like the NFL, has no prohibition against the practice. The same is not true in high school football, however. Under National Federation of State High School Associations rules, face guarding counts as pass interference. The rule defines the infraction in rule 7-5-10: "Any player hinders an opponent's vision without making an attempt to catch, intercept or bat the ball, even though no contact was made."