What kind of photos can be used in android app?

Question

Google Play

I am interested in the legal side of the issue. I heard that google play can ban an account for using someone else's images, is this true? For example, I need a background for the login page, I found a suitable photo in Yandex pictures, cropped it, put it in the application and want to publish it in the market. Is there a risk?
And the icons are the same. For example Ionicons - their website says "Completely open source, MIT licensed and built by the Ionic Framework team". Wikipedia told me that MIT "allows programmers to use licensed code in proprietary software, provided the license text is provided with the software." And then I stopped understanding anything at all

Answer 1

There is a great pack of icons from Google that you can use for free. Regarding the background of the application, only if the author of the picture burns you. Yes, and Open Source content is full.