Actually Doc Mac, they do NOT have a "right" to protest at a privately held organization or entity. Your 1st amendment rights are protections against a government's interference or encroachments.  But in this case, there is and was no government interference in the first place causing anyone to assert their "rights".  You do not have 1st amendment specific protections in the workplace.  Now, if the NFL doesn't do anything to stop them, that's on them and it's their choice to fire or keep them.  It's no different than... you or I do not have a constitutional "right" to protest at OUR workplace, otherwise we take the risk of being fired. And if a contract was signed and you do not fulfill said contract because you've chosen to "protest," then you also run the risk of possible legal ramifications.  Hope that clarifies.