She was one of the main reasons that tennis made a decision to investigate video replay technology on the courts after several bad calls went against her in the 2004 US Open quarterfinals, she has been described as "scary" to look at by the president of the Russian Tennis Federation, she has been handed penalties that wouldn't otherwise have been given to men.
The Japanese player's breakthrough triumph in NY was overshadowed by an explosive row between her opponent Williams and umpire Carlos Ramos which resulted in the 23-times Grand Slam champion being docked a game and fined $17,000 (£12,975).
The 23-time Grand Slam champion had another running battle last Saturday with umpire Carlos Ramos, calling him a "liar" and a "thief" after he issued her a code violation for receiving coaching from Patrick Mouratoglou, which she vehemently denied. You are the best player at the end of this event and because of the turn of events with the crowd and the booing and everything, it wasn't the way - that was the outcome I was referring to. I have never cheated in my life!
Following the match Williams cited sexism as the reason for her punishment, claiming that she had been treated more harshly than a man would have been. Speaking on ESPN, McEnroe backed Serena, who called the chair umpire Carlos Ramos as a "thief".
Umpires could refuse to accept the chair when Williams competes, but would call off the apparent protest if Williams apologises for her remarks.
According to reports, she's agreed to an endorsement deal with Adidas that will pay her $8.5 million per year, which would be the richest deal in women's tennis. "I think it's a matter of having a conversation with the two guys and saying let's cut it out, let's slow it down, and then perhaps not understanding how they can have the same conversation with the females".
Even the International Tennis Federation (ITF), which stood by the judges, waited 48 hours before announcing a position.
Adams noted that Ramos was "following the code", but added that a "soft" warning for coaching could have averted the blowup over something that happens frequently on the men's and women's sides. "The fact that I have to go through this is just an example for the next person that has emotions and wants to express themselves and wants to be strong woman".