I am also wondering why I haven't written anything here! Cache is a breathtakingly dense film while being an exercise in formal economy. It gathers within its almost two-hour runtime the very contemporary and manifestly political concerns (explored in his other films) about surveillance society and its associated voyeurism (Funny Games, Benny's Video), race/power relations (Code Unknown), violence and its consumption (Funny Games, Piano Teacher) and the interrogation of film as a medium.

I agree with wpqx about Cache not being a whodunnit. In fact, that question is perhaps the least important one to ask of a film that consistently averts narrative closure, while deliberately enticing the viewer to fill the gaps by misreading it as a whodunnit game. A highly self-referential film, Cache's eerie opening and closing shots defy the viewer by not providing the reverse shot and releasing the suspense/tension about the nature of the surveillance, whether human or spectral. Effectively it denies the viewer the relief and the reassurance of a narrative, whose bits and pieces can be stitched together coherently. As arsaib puts it (in his review of The Seventh Continent), 'there is special talent at work here'. Haneke is growing on me and I need to revisit the ones I've seen. I am yet to see The Seventh Continent and more, but most desperate to lay my hands on Haneke's take on Kafka, The Castle! 

M