KARACHI - Jamaat-e-Islami (JI) Karachi staged a big sit-in protest outside the Karachi Water and Sewerage Board headquarters against acute water shortage in the city, patronage of tanker mafias on governmental level and unjust distribution of potable water.    A large number of people, belonging to all walks of life, the affected people, besides chairmen of nine towns and 88 union councils in Karachi participated in the protest demonstration.  The sit-in was initiated in the evening and continued till night. The affected people carrying placards and banners chanted slogans against the PPP government, the installed mayor and the water board. On the occasion, a large number of affected people from different areas of the city shared their ordeal.