Trace the path of the brake cable. Then turn the bar back and forth while looking around. Anything pop out at you?

I don't think rust explains something seizing up so tightly that it would pull the brakes enough to possibly bring you down. It seems like something else is catching somewhere.

Is it possible the rain got into the cable housings and froze, causing the cable to seize up somewhere.

I hope the rest of you jerks are happy with yourselves after cracking jokes about the camera of a guy who came here for help. The picture wasn't even really necessary to offer ideas of things to look for. It's sadly reflective of the bully mentality present in today's America.