A: The cooperation of volunteers in any country with the security forces against corruption is considered Jihad (fighting/striving in the Cause of Allah) for whomever Allah has granted sincere intention. It comes under AlRibat for the Sake of Allah, which means keeping a guarding army ready to defend Muslims' frontiers against enemies.
As for those who strive hard in Us (Our Cause), We will surely guide them to Our Paths (i.e. Allâh's religion Islâmic Monotheism). And verily, Allâh is with the Muhsinûn (good doers).
The Prophet (peace be upon him) said: Never had Allah sent a Prophet before me to a nation but he had among his people (his) disciples and companions who followed his way and obeyed his command. Then, there came after them their successors who said whatever they did not practice and practiced whatever they were not commanded to do. He who strives against them with his hand is a believer: he who strives against them with his tongue is a believer, and he who strives against them with his heart is a believer and beyond that there is no faith even to the extent of a mustard seed. (Related by Imam Muslim in his Sahih (authentic) Bookon the authority of `Abdullah ibn Mas`ud [may Allah be pleased with him]).