Pedestrians *in* a crosswalk have the right of way; however, at signalized intersections, pedestrians waiting to enter the crosswalk do not. They must obey the signals.
In other words, if someone is waiting at the curb to use a crosswalk in the middle of the street somewhere, you are legally obliged to stop and let them cross. You can be ticketed for not doing so. However, if the same person is waiting at a crosswalk at an intersection and "Don't Walk" is displayed, you do not have to stop for them, they have to wait on the curb. If a pedestrian is in a crosswalk for whatever reason, you must stop and let them finish otherwise there are a number of different reasons you can be ticketed. However, you needn't stop for them if they're on the other side of a divided road. In Massachusetts, anyway.