The war between Wall Street traders just stepped up a notch

A war of words between Wall Street traders just stepped up a notch. 
It's a battle that has been playing out for some time, typically between market participants behind closed doors. 
Stock exchanges — in particular the New York Stock Exchange and Nasdaq — both publicly traded and for-profit, stand accused by rivals and some users of unfairly increasing the price of market data, connectivity, and colocation.  
The exchanges, in contrast, argue that these feeds are