Snapchat CEO Evan Spiegel. Youtube/Snapchat Snapchat recently updated its privacy policy in part because it is launching Snapcash, a new function that lets users send payments to each other via Snapchat. But Snapchat also did everyone a favor by rewriting that privacy policy in plain English.

So now we can see exactly what Snapchat knows about you, and how the app tracks you.

Users will be surprised to learn that unless they spend time in the app's settings revoking Snapchat's various privileges, Snapchat can end up knowing pretty much everything about you — your name, your exact location right now, who your friends are, and when you message them.

You don't give your name to Snapchat when you sign up for the app, but Snapchat knows it anyway, the new policy says. The company collects this data because it's useful for advertisers, the privacy policy says.

Most people use Snapchat because they like the way messages are instantly deleted, and it feels more private and secure than using regular text messages on your phone. But it's actually not very anonymous at all.

It's important to state that users can revoke many of Snapchat's permissions if they want to. But doing so will stop some of the functions in the app. They can also delete the app. But even then, Snapchat keeps some of your data for a period, the policy says.

Here's a list of the data Snapchat has on you:

• Your contact list. You didn't give the app your name, and in the Snapchat world you're just "Cuddlybear78," or whatever. But Snapchat does get the names of contacts in your phone. And that means Snapchat will have your name from the contact list of anyone else you communicate with on Snapchat. You can revoke this permission in the app's settings.

• Your name. The company admits it trawls contact lists in a separate entry in its privacy policy about the information it collects on you from "other sources": "If another user allows us to collect information from his or her device phone book—and you’re one of that user’s contacts—we may combine the information we collect from that user’s phone book with other information we have collected about you. We may also obtain information from other sources and combine that with the information we collect through Snapchat."

• Your photos. "Because Snapchat is all about communicating with friends, we may—with your consent—collect information from your device’s phonebook and photos," the policy says.

• Your location. Snapchat tracks your real life location via "beacons." Beacons are favored by Apple and its iBeacon system. Most people aren't aware thee things even exist yet. Beacons send out a low-range Bluetooth signal that can ping your phone as you walk by. Retailers like them because the can tracks shoppers in stores. Any app such as Snapchat will then be able to know exactly when and where you are, down to a few feet. You can switch this off. (Again, you can revoke this in the settings.)

• Your web browsing history. Snapchat has permission to track you with cookies. Most people know that cookies are used to track your history as you browse the web, particularly on Android phones.

• Snapchat shares data that may be useful to advertisers with Flurry, the mobile ad company now owned by Yahoo. This data is anonymous and aggregated, and frankly you shouldn't worry too much about it. Just be aware that Snapchat is just like any other digital ad media company — it's not some super-secure anonymous service.

• Your email address.

• Your debit/credit card number (if you use Snapcash).

• Your card's "associated account information," which probably means your name and address.

• Everything about the "snaps" (messages) you send to others except what is in them: "time, date, sender, recipient of a message, the number of messages you exchange with your friends, which friends you exchange messages with the most, and your interactions with messages (such as when you open a message or capture a screenshot)."

• The type of phone you use and a unique code that identifies it.

• Even if you delete your account, "keep in mind that we may retain certain information in backup for a limited period of time or as required by law," Snapchat says.