Ah man, child pornography, once again the edge case that screws up reasonable planning. Can't explain, for fear that if the user wasn't really guilty, you're taking a pretty serious step in accusing them of peddling child pornography. And also can't give them their data, for fear that if they were guilty, you're redistributing child pornography.
The only thing that might be nice, besides some personalized review of hard edge cases, is to allow users to export "untainted" data, if it can somehow be isolated. E.g. if one gallery was flagged, still let him export his uncontroversial email archives.
