"All-seeing commenter Fatima at palestinianpundit calls attention to an article in the current issue of the Egyptian weekly paper AlOsboa, whose first two paragraphs go like this:
Political sources told Al-Osboa that Cairo changed its attitude to the Hamas movement after Hamas provided the Egyptian security apparatus with information showing the involvement of certain leaders in the Palestinian Preventive Security and Fatah in a number of suspicious schemes against Egypt.
The sources said Hamas leaders provided Cairo with conclusive evidence of the involvement of one of these [Fatah] leaders in the transmission to Israel of information concerning Egyptian security and political situations, including [information garnered in the course of] meetings that this official had with a number of [Egyptian] officials in the course of his repeated visits to Cairo.
This supports what has been reported earlier about the importance of the Gaza intelligence bonanza to Hamas-Egypt relations.
Unfortunately, as the aforementioned Fatima noted, the link to the full article isn't working, so I suggest checking back there from time to time. And while you're there I recommend reading carefully the main post and in particular the linked 1982 Israeli position paper on Mideast strategy with its contemporary-sounding references to a tripartite splitup of Iraq, giving the West Bank Palestinians to Jordan, and all the rest of it."