Snapchat billboardReutersA Snapchat billboard hangs in Times Square.

A recent change to Snapchat's terms of service and privacy policy has some people worried about how the social network is collecting information about its users. 

Language in the updated terms of service, which Snapchatters must accept to use the app after this week's update, describes the social network as able to "access, review, screen, and delete" content shared in the app "for any reason." It also says Snapchat can "publicly display that content in any form," including with its "business partners."

The new terms can sound scary coming from a social network that built its name on messages that supposedly disappear forever after 10 seconds. Kal Penn, who starred in the "Harold and Kumar" movies (and who has worked in the White House for President Obama) called Snapchat's new terms "scary stuff."

Data gathering on users is a common practice for social networks — Instagram, Twitter, and Facebook all have similar condition for what you publicly share on their networks. And given that Snapchat is letting advertisers market with Live Stories, it's safe to assume that Snapchat wants to monetize around what you share publicly through the app.

But to fully grasp Snapchat's stance on privacy and the data it's gathering from users, it's important to understand how the app works and how you should be using it. (Snapchat declined to comment for this story.)

There are essentially two ways of sending messages, or "snaps," in Snapchat. You can send photos or videos directly to other people you're friends with or who follow you.

You can also make your snaps part of a Live Story, which is a collection of croudsourced snaps for a specific event or region.

IMG_2809.PNGTech InsiderSnapchat Discover and curated Live Stories are accessible above your friends' stories in the app.

Live stories can generally be viewed by anyone on Snapchat, like in the case of the recent GOP debate or for big events like MTV's Video Music Awards. These stories are curated by Snapchat to include only relevant snaps from an event or area. They also expire in the app after 24 hours.

You have to willingly submit a snap to be considered for a Live Story, and if it's selected, you should expect that thousands of people will see it — not just your friends. According to Snapchat's terms and conditions, appearing in a Live Story means you give Snapchat "unrestricted, worldwide, perpetual right and license to use your name, likeness, and voice in any and all media and distribution channels."

There's also Snapchat Discover to consider, a relatively new part of the Snapchat app that lets content makers like Vice and CNN share exclusive video and interactive stories. Discover partners know how many people are viewing their content, including information like age demographics.

When you send a snap directly to another person, Snapchat still deletes the photo or video from its servers after it's viewed by the other party. Nothing has changed there. Advertisers aren't able to see the private messages you're sending your significant other in the app.

Another potential scare in Snapchat's privacy policy was pointed out on Twitter Thursday:

The log information Snapchat says it collects, including "pages you visited before navigating to our services" refers to its own website, not your normal web browsing behavior elsewhere. The Snapchat app isn't seeing what website you visited in Safari on your iPhone before you open Snapchat.

As with any service, it's important to read the terms of service and privacy policy you agree to. Thankfully, Snapchat's is written without much of the legal jargon companies frequently use to obfuscate their shady tactics. Snapchat CEO Evan Spiegel has been very clear about how he's against targeted advertising and respecting customer privacy.

If Snapchat does share information about you with advertisers, like your age, it will only share "aggregated or de-identified information that cannot reasonably be used to identify you," according to its privacy policy. Still, you shouldn't expect that just because Snapchat messages eventually expire, your data isn't ever accessible.

As the age old saying goes, if you aren't paying for the product, you are the product.