When you use services like Facebook or Instagram, they are collecting some amount of information about you that can be used by third parties. Even though Facebook has started to curve more into a privacy-focused company, there are still using your information to an extent. So be careful what you do on Facebook. And with FaceApp being very popular right now, there are some privacy concerns when using that app. In its Term of Service, you are giving the company the rights to use your photos of you in whichever way they want.
Overall, be aware of any company's Terms of Service when using their services of apps.