Why were women in France in the 1940s shaving their heads?

Many ladies were dragged to the streets and publicly humiliated after the Allies liberated France.

These women were charged with "horizontal cooperation." To hide their most attractive features, their heads were shaved. All of them would be paraded around the streets, some with tar or lipstick painted on their nude bodies.

The majority of these 'collaborators' were merely young ladies who had slept with the German occupiers. Some of them would even parade around with the children they had with the Germans. Some were compelled to, others fell in love, and some had to sleep with Germans to earn food. It made little difference to the French because everyone would then be labelled a traitor and publically humiliated. These actions outraged the Allies and even some French people.

These activities also happened in Belgium, Italy, Norway and the Netherlands. (However, it wasn't as common in the Netherlands.)