During an appearance at CES 2013 in Las Vegas, Legere was discussing how T-Mobile's network in New York City is better than Verizon and AT&T service in the city. He speaks to someone in the audience from New York and is an AT&T customer who apparently isn't happy with his service. Legere then calls AT&T's network "crap".
Check out the video below to see Legere make his four letter assessment of his rival. He takes the stage at the 1:22 mark.
source: MobileWorldLive via TmoNews