3Real Estate Mafia
In towns, cities and metros, real estate is a big source of black money. In India, a large percentage of land deals are underreported. Whenever you go to a builder to see a flat, you always have to pay from 20 up to 40 percent of the cost in cash. No builder takes 100% cash and they are able to hide a significant part of their income from tax authorities. With demonetization, they will not be able to provide the sources of their illegally acquired money or face heavy penalties.
Also, with the increased use of technology in land records keeping it would make land deals more transparent. Also cases like Adarsh society scam will not happen with all government lands recorded in the system making it difficult for land hoarders to illegally make constructions on them. All these steps would break the builder politician nexus as well resulting in cheaper homes for home buyers. This will bring down the amount of black money in elections as well making it more possible for honest citizens to fight elections.