Hamas arrested 50 Fatah members at a meeting in Gaza, on the eve of the unification negotiations in Cairo. This must be what is called a "confidence-building measure" in that part of the world.
And since they were in the mood, Hamas also arrested three journalists from Fatah's Ramattan News Agency. (I saw that they had detained an AFP reporter yesterday but cannot find the story now. Reporters Without Borders, as usual, is silent.)
And for the hat-trick, Hamas also raided some sort of computer laboratory in Gaza City, also associated with Fatah, and arrested the Fatah-linked governor of Gaza there.