Your Life in Metadata

Bob is in an elevator, running late as usual. Mary sent him a flurry of annoying texts earlier, and he is only now responding. He doesn't have time to argue; he shoots off a quick "K!" and carries on.

Bob’s and Mary's phones are endpoints in a massive interconnected grid, full of complex transmissions in every direction over billions of possible pathways using relatively simple routing protocols. Here is a very abbreviated itinerary for Bob's text:

1. Bob's phone beams the message to a nearby cell tower, the tower confirms receipt.

2. The message is passed to a node closer to Mary; the node confirms receipt.

3. Repeat (2)
...
n. Repeat (2)
n+1. The message hits the cell tower in contact with Mary's phone
n+2. The message lands on Mary's phone 

The message itself (a.k.a. the data) is only about two bytes, but here is a truncated list of trivia (a.k.a. the metadata) associated with each step above:

1. Date and time received
2. Most recent source node
3. Immediate destination node
4. Date and time of transmission to next node
5. Date and time of acknowledgement by next node

The metadata is necessary to the transmission process, but it is useful for more than that. Here are just some factoids a phone carrier, at the hands of a talented data scientist, may surmise from a large collection of these continuously accumulating data points:

1. Average number of daily messages from a given location to any other location
2. Average number of daily messages from a given location to another given location
3. Most common areas for message transmission, reception, and relay
4. Average delay of a message at any given relay point
5. Lists of relay points that are overused and underused for the resources allotted 

These reports are essential for improving the country’s infrastructure. While the message data is protected by the carrier’s privacy policy and various applicable laws, the metadata is very much a product of the carrier’s machinery, and could likely be considered the carrier’s property.

Does the data have uses beyond that? Almost definitely.

Can carriers share the metadata with other companies? With the federal government? Yes, and they do.

Should they be doing so? This is hard to say. Metadata has the potential to reveal almost as much as (or more than) content itself.

Laws governing the storage and dissemination of metadata have to mitigate various civil, commercial, and governmental concerns. If framed properly, it is an important national conversation.