Wigner crystal and FQH effect are both due to strong electron-electron interaction under magnetic field. As we know, Landau's symmetry-breaking cannot be used to describe FQH state. But can it be used to describe Wigner crystal state and which symmetries are broken in Wigner crystal?
As the name "crystal" implies, the Wigner crystal is defined by broken translational symmetry and the formation of a crystal lattice. This is mentioned in the first paragraph of the Wikipedia entry.