WarViewing (also known as War Watching and Warspying) is the sport and hunt for unprotected 2.4 GHz video feeds. These are usually broadcast from X10 cameras in major cities from traffic cameras, lobbies, or locally owned shops. WarViewing is derived from the term WarDriving (where people drive around with Wi-Fi equipment and look for wireless computer networks) which was originally derived from Wardialing (an outdated practice where people would use a modem to brute-force dial phone numbers searching for other computer modems which would answer).
War viewing involves travelling around either in a vehicle or on foot and using a video receiver and screen to view transmissions (usually) in the 2.4 GHz license free ISM band. This is a set of international frequency allocations that are intended for a number of public uses, but the 2.4 GHz allocation is predominantly used for wireless cameras, home video senders and Wi-Fi computer networks.
War Viewers will usually mount an external omni-directional antenna to a vehicle to extend the limited range of reception (much like War Drivers do). Expected ranges in an urban environment can be from as little as a few metres up to about 50 metres, although longer ranges are possible with directional antennas, higher quality equipment or particularly favourable conditions.
A small screen and openly available 2.4 GHz video receiver is usually used to see what video transmissions there are out there. Finds can include wireless covert surveillance cameras, CCTV cameras, TV senders, home video senders, X10 cameras, etc.
Wi-Fi networks currently share approximately the same frequency band as the video transmissions, which means that the antennas used are interchangeable.
If war viewing is done on foot, then sometimes a directional antenna like a patch antenna or yagi antenna is used to try and pinpoint the exact location of a transmitter, and to cut down on interference.