brake question?

Yesterday was a rare nice day here in Virginia Beach so me and the owners of the shop I hang out at wanted to go for a drive and hit up a mustang show, so we get on the highway and play around (they both have 600+ hp Cobra's) well they play and I just try to keep up... it didnt work anyway to get to the point I had to keep getting on the brakes pretty hard (traffic,red lights) well we get to this one light any they have the line, they take off I try to keep up but once again have to get on the brakes this time hard cause I was going about 100 well when I stopped smoke started pouring out of my front tires so I pull off and give them a sec to cool down... what might of happened to my brakes? anyone ever done this before?