Hyderabad police nabbed several cyber criminals, who hacked the computers and got hold of ATM card and debit card numbers and walked away with huge sums. Several such cases are being reported every month, the police said. The modus operandi of these cheaters was to call up anyone at random, indentify themselves as bank officials, and ask the customers their debit card numbers, or ATM card numbers. Most of the cyber criminals are from Jharkhand state, they said. They cautioned customers against revealing card details.