The ACLU today wrote to the CEOs of the nation’s major cell phone providers asking that they stop routinely collecting and storing data on their customers’ daily movements. We’re also urging Americans to make this same demand, and we’ve created a page making it easy to do so.

The fact is our cell phone companies know more about where we are throughout the day than our closest friends. One of the byproducts of the way cell phones work – staying in constant touch with the nearest cell tower – is that our carriers can tell roughly where we are. And over time, that data is getting increasingly accurate.

But the major carriers – AT&T, Verizon, T-Mobile and Sprint – don’t just know where we are from moment to moment. They also retain detailed data about our location for extended periods of time, as we learned recently when we received this document in response to our national public records request on how the authorities are using location data. The carriers also readily share the information they gather with government agencies and law enforcement.

Why should they be doing all this?

We pay them money, they provide us with phone and data services. Being tracked everywhere we go was never part of the bargain.

We don’t know exactly how precise the data the carriers retain is, or how they are using it. Often these days there is often an automatic, reflexive impulse to retain data – any and all. But it also seems that the companies are looking at how to monetize this information as they do with other information they gather. Verizon, for example, recently announced that it was selling location information about its customers. Although it is doing so only on an aggregate basis, that still represents a step closer to sharing our own individual movements, which the carriers are surely tempted to do.

Either way, if we roll over and accept this practice, then we’ll be accepting a world that totalitarian dictators can only dream of: an entire population carrying location tracking beacons that precisely record their every movement. This is not something we should be just taking in stride. It’s not something that we have to accept.

The best protection for privacy is for the carriers to not record our locations, even though the phone reveals them, unless we decide to give permission (and not through the fine print in some boilerplate click-through agreement). We should demand nothing less.

It’s time to put on the pressure. The ACLU has asked the mobile carriers to stop retaining data about our movements. Join us in demanding that your carrier to do the same.

Learn more about location tracking: Sign up for breaking news alerts, follow us on Twitter, and like us on Facebook.