It is hotly debated whether these secretive people are a religion, sufferers of a sickness or hysteria, or even the victims of a malevolent alien parasite which takes over their will.
In any case, it sometimes happens that a person will abruptly leave their life behind, move to a new district of the city, and live a life of voluntary destitution, sleeping on the streets and living off garbage. They maintain a total silence (at least when outsiders are around), disdaining even to beg. Such people are usually young, and tend to be better-educated and more intelligent than the average.
They appear to be able to distinguish themselves from both the involuntarily destitute, and those who mimic their lifestyle in an attempt to study them, rendering information about them difficult to come by. However some scholars claim that their search for food scraps is a sham, and that in reality they eat metal. Some speculate that they may have the maniacal belief that they can become robots by this method.