Step 1 : Introduction to the question "why is everyone mad at antonio brown"
...Steelers receiver Antonio Brown did not play in the season-ending game against the Cincinnati Bengals because he elected to sit out practice last week after an unspecified heated dispute with a teammate, the Pittsburgh Post-Gazette has learned.Brown then refused to practice because the helmet he preferred was banned in the off-season by the N.F.L. and the players union because it, and other models, did not meet safety standards. This week Brown announced via video on the helmet-maker's website that he had found a replacement.