First of all, we need to keep in mind that wearing thread is part of Indo-pak culture. Iranainas, Arab or Azeri-Turk Shias do not practice it. Yes, almost all the Shias do have alams in their communities. The philosophy behind it could be commemoration of the great sacrifice of Hazrat Abbas (as). The Maraje do give permission to hold alams in processions and we should learn lessons of loyalty, obedience and submission from this practice.