In the end it was the easiest of cases to crack for the National Investigation Agency (NIA). The accused Birju Kishor Salla (37), scion of a family of jewellers from Mumbai, had already confessed to planting a hijack threat in the toilet of a Jet Airways Mumbai-Delhi flight to the police. The A4 size paper on which the threat was printed matched papers lying in Salla’s office. The ink with which it was printed matched the ink of his office printer. Salla’s laptop revealed that hijack threat was printed on his office printer. His Google cache showed he had used