Hamas' most problematic demand concerning the hostage deal is for the organization to have full control over which "heavy" Palestinian prisoners are to be released. Israel cannot agree to this, and Hamas officials know this. They remember the negotiations for the release of Gilad Shalit. A similar deal was proposed, but in the end it was decided that Israel and Hamas would decide together who would be released and who would remain in Israeli custody. Hamas relayed lists of names, Israel made deletions and passed them back, Hamas dug in, Israel wavered. The talks collapsed more than once over exactly this issue.