body: I am a software developer and i am working on a mobile app, in which i am using images.
  I took all these images from a website, and according to this website, they all have a Creative Commons Zero (CCO) license, so i am sure i can use them.
  
  
  I ended up downloading them and using them in my mobile app.
  However i have a feeling that it's not enough.
  
  
  Let's imagine someone wants to sue me saying the images i use don't have license, how can i proove him i am right ?
  Just sayin "i read the website and drag and dropped" seems a bit messy to me.
  
  
  Is there any legal document i should do or any best practices, so i will be sure i won't get sued ?
  
  
  I want to be sure i can proove i am in my right
  
  
  
title: How to use CC0 license?