I don't know if you ever heard about "Biribi" and "les bat d'af" ("African battalions")...Biribi is the name given in France to the punishment battalions in Algeria. Every young man who has been in prison before he begins his military service, was sent to such a battalion. Many soldiers, for lack of discipline, undergo the same punishment. The treatment in these places was so tough that no one would believe it possible. Men were left for weeks in holes dug in desert, and some were actually devoured by vermin. At this time, it was quite habitual to let a man, handcuffed and chained, lay for a fortnight on the ground, covered by a bit of cloth, under the scorching sun of Algeria and through the bitterly cold nights, compelled to eat his food and to lap his water like a dog.
Scores of the most terrible facts became known lately.
more info @ (french)
original picture @ (english)
Read this to learn more about French prisoners tattoos.