[3][4] Negative databases can avoid inappropriate queries and inferences.
[5] Under this scenario, it is desirable that the database support only the allowable queries while protecting the privacy of individual records, say from inspection by an insider.
Negative databases achieve this by storing the complement of the set of what is being tracked.
Extending his approach the negative intelligence gatherer would seek to understand what websites, infrastructure systems, environmental sensors or documents have become unavailable.
The negative sousveillance concept then is to record, track, or infer what isn’t there."