When an American tennis player starts getting irate with the rules of 'soccer' then you know something interesting is happening.
Even Andy Roddick felt moved to tweet his displeasure at the decision not to allow Frank Lampard's goal against Germany, and Roddick is better placed than most to comment on the potential benefits technology can bring to a sport.
Line decisions in tennis can now be referred to video replays and broadly speaking the players like the system.
Unfortunately Fifa president Sep Blatter is one man who does not like the idea.