India’s foreign secretary, Shiv Shankar Menon – an ex High Commissioner from India to Pakistan – has said that “it is hard to believe” that the Mumbai attack, commando style as they were, could be carried out without anybody, anywhere in the (Pak) establishment knowing that this was happening. 
He should know. Most Indian consulate members are victims of high handedness from ISI. It is customary in a lot of gatherings in Delhi to invite the Pakistani High Commissioners and the peaceniks love to get their photos taken with them. But whenever the similar invites have been given to Indian High Commissioners in Islamabad, even for a simple meal, they get a very harsh treatment from ISI.
It is also a fact that Pakistani ISI establishment hardly follows any civilized policies. They are known to beat up Indian diplomats whenever a Pakistani diplomat is expelled from Pak consulate in Delhi. Almost 70-80% of the staff in Pak consulate is from ISI. 
While US is becoming amenable to bringing criminals to Pakistan courts, India – rightfully so – is asking for the criminals within Pakistan to be handed over so they can be brought to Indian justice! I am convinced that short of eliminating them within Pakistan through direct strikes or covert operations, India should put the force behind getting these criminals in India.