Instagram is updating its privacy policy and terms of service. The biggest changes are about how photographs users upload may be used by Instagram and its parent company, Facebook.

The changes, which will go into effect Jan. 16, will not apply to pictures shared before that date.
Some of the policy is written in lengthy and hard to understand language. Here’s a summary of what these changes mean for you.

1. Instagram can share information about its users with Facebook, its parent company, as well as outside affiliates and advertisers.
Basically, this means that the information you include in your Instagram profile can be passed around to Facebook and other affiliates and advertisers. Details such as your hobbies, favorites, etc., can possibly be shared with potential advertisers so they can better target ads.

 2. You could star in an advertisement — without your knowledge.
Instagram will also be able to use your photographs and identity in advertisements. “You agree that a business or other entity may pay us to display your username, likeness, photos (along with any associated metadata), and/or actions you take, in connection with paid or sponsored content or promotions, without any compensation to you,” the new terms say. This means that photographs uploaded to Instagram could end up in an advertisement.

3. Underage users are not exempt.
Athough Instagram says people must be at least 13 years old to sign up for the service, the new terms note that if a teenager signs up, they are agreeing that a parent or guardian is aware that their image, username and photos can also be used in ads.

4. Want to opt out? Delete your account.
The only way to opt out of the new Instagram terms is to not use the service. Period.