Gurugram, Jan. 16 -- Starting Friday, policemen in mufti will keep vigil at all party destinations across the city and at all intercity and inter-state border roads to prevent smuggling of narcotics. Police said they hope the drive will help them crack the heroin and cocaine supply routes and nab those who are peddling narcotics in the national capital region. Police are also preparing a database of foreigners visiting Delhi-NCR and of party organisers and drug peddlers, who are using social media, including Facebook, Twitter and WhatsApp, to send invites. "The STF is trying to track them by searching keywords and code words used by addicts," polices aid....