Today, in TV there was news about a district in Kerala (Malappuram) having 50000 crores worth of old currency in the hands of various people there. The person whom the reporter interviewed was an agent who sold these old notes to some people for a percentage of the value of the old notes. They didn't say for what purpose the old notes are bought. A friend of mine who knows some Gujrathi cloth merchants in Kochi's main market was told these old notes are bought so that its thread can be taken for counterfeiting new notes.