The nice thing about magnetic fields is that all charged particles are deflected: the positive ones bend one way, and the negative ones bend the other.

In a lot of situations, the particles will actually spin along helical paths whose net motion is along the magnetic field lines. In the case of Earth, that means that the charged particles eventually make their way to one or the other pole... and as the field lines descend into the atmosphere, those particles create auroras. Neat stuff!