NFL players have been locking arms during the playing of the national anthem for the same reason that they have been kneeling, sitting, or not even coming out of the locker room. They are protesting racism in our country.
Many players joined in on the protest after Donald Trump made some very negative and unprofessional comments about the protests that had already been going on. In addition to players some coaches and even team owners have also been either kneeling, locking arms in solidarity or staying in the locker room until the national anthem
has been played.