This guy is a non-stop taunting machine on and off the field. He back talks the refs; mocks the other team members, their families, their cities, etc...; and trash talks and taunts them whenever they make a mistake and he does it constantly. People are really sick of him in the NFL and he's gotten away with more of it than any player I'm aware of.
Here's a picture of him getting punched square in the face after saying some cruel things to another person on the field during the game and yes Trent Williams was fined and disciplined by the NFL for punching him:
[video=youtube_share;Wl4ViIwy7KA]http://youtu.be/Wl4ViIwy7KA[/video]
The NFL has official league safety rules and distributes a League Policies for Players manual to all players and coaches at the start of training camp every year.
In the manual, sportsmanship is communicated as a cornerstone of the game of football and of vital concern to everyone involved in the game, including players, coaches, officials, and League personnel. The reasons they list for this are broad and include safety reasons.
They spell out that the term sportsmanship conveys respect for the game, respect for opponents, respect for the game officials, and respect for the fans.
They state that the League will not tolerate unsportsmanlike conduct. This applies to any act which is contrary to the generally understood principles of sportsmanship. Unsportsmanlike conduct is also discussed in Rule 12, Section 3 of the Official Playing Rules of the National Football League ("NFL Rule Book").
Officials are authorized to immediately call a foul if any unsportsmanlike conduct occurs anywhere on the field.
It is important to note that the unsportsmanlike conduct rules apply to all personnel in the team area, including players, coaches, team employees, and officials and at other times, including postgame interviews.
Unsportsmanlike conduct includes abusive, threatening, insulting, or profane language or gestures, and physical acts by coaches, players, and other club personnel directed at opponents, officials, game personnel, or fans.
NFL games are broadcast on radio and television and there are open microphones near the playing field as well as closeup camera shots that permit easy lip-reading by viewers.
Keep in mind that the League and its participants are severely criticized whenever obscene or profane language or obscene gestures are carried or shown on the air and the NFL has a history of levying disciplinary action when it occurs.
And note that every player's contract includes provisions for sportsmanlike conduct which they agree to when they sign the contract.
Yes this is a first amendment issue. You're right. But it's different for a player than it is a fan. Read this for more information:
http://scholarship.law.marquette.edu/cgi/viewcontent.cgi?article=1275&context=sportslaw&sei-redir=1&referer=http%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26rct%3Dj%26q%3Dfirst%2520amendment%2520and%2520professional%2520athletes%26source%3Dweb%26cd%3D1%26cad%3Drja%26ved%3D0CCQQFjAA%26url%3Dhttp%253A%252F%252Fscholarship.law.marquette.edu%252Fcgi%252Fviewcontent.cgi%253Farticle%253D1275%2526context%253Dsportslaw%26ei%3DSUPjUqeUEIWGogSgsIGwAQ%26usg%3DAFQjCNHkXBQugHMGuTZAUP-iOW5X0Pr3Wg%26sig2%3Di7WJr4fFHURqQP-m2Bqkzg%26bvm%3Dbv.59930103%2Cd.cGU#search=%22first%20amendment%20professional%20athletes%22