A website looks better with fitting pictures. While designing my website I am using Google images to search for the right pictures (next time I will probably use a website that stores free images). Using a copyrighted picture, when I know who created it or to which company the copyright belongs is definitely not a big deal, since I can contact them and ask them for using it on my page (non-commercial).
However, there are these websites that store wallpapers. They usually don't have a source, either. And in their ToS they tell that if you want to use a wallpaper of their site, you gotta ask the copyright holder (which is unknown in this case).
But after all they are using copyrighted pictures as well, and they write: "If you find copyrighted material on our page, contact us and we will remove it for you."
So here are my questions:
1) How can companies use copyrighted pictures and avoid getting sued? On top of that, they are a commercial page.
2) Can I do the same? (if the source of a picture is unknown and/or from such a wallpaper website)