Police can’t read your iMessages, but here’s what they can see

While Apple has made a big deal over the past few years about how little customer data it stores on its servers, that doesn’t mean the iPhone maker doesn’t have any information that police agencies can get their hands on.

As noted by The Intercept, one thing Apple knows is which phone numbers a person is at least considering sending a message to. That’s because as soon as an iPhone owner types in a phone number, Apple’s servers are pinged to determine whether the number represents another iOS device.

If so, Apple will send any messages using its own service (they appear in a blue bubble). If not, Apple will send any messages as a standard text message (displayed in green).

That Apple’s servers would be pinged with every number a person is messaging should not come as a surprise. After all, how else would the iPhone know how to send the message?

More of a revelation was the fact that Apple stores the information for 30 days. Choosing how to send messages is tricky and has caused Apple problems in the past, especially when a user switches from iPhone to Android.

About three and a half years ago, Apple engineers started storing a cache of which numbers customers were trying to message in order to help identify bugs and address customer complaints, according to a source familiar with the company’s efforts.

So what does all this mean? Apple still has far less information about its messages than a cellular provider has on its customers’ standard text messages. Carriers would likely be able to determine not only exactly what message was sent and when, but also where the customer was when they sent it.

Apple, for its part, doesn’t appear to even know if a message was sent to a particular number or details on any follow-up conversations — only that at one point a number was typed into an iOS device.

The iPhone maker has always said that it will share data it has access to with law enforcement agencies upon a lawful request, such as a warrant or other court order.

However, since Apple has crowed about how little data it stores on its customers, it’s definitely worth knowing what information it does keep.

“Because iMessage is encrypted end-to-end, we do not have access to the contents of those communications,” Apple said. “In some cases, we are able to provide data from server logs that are generated from customers accessing certain apps on their devices.”

All this is a reminder that just because a message is encrypted doesn’t mean that there are no digital breadcrumbs left behind.

This article originally appeared on Recode.net.