As Joaquín Muñoz, Head of IT and IP at ONTIER, explained for the online daily prnoticias.com, the author ''always owns their copyright''. ''Every image has a copyright to protect their use'' and it's the author who decides whether or not they can be used and how.
Muñoz however notes that there's a twist to this when it comes to images uploaded to social media platforms: ''When users agree to the terms and conditions of social media platforms, they allow said platforms to own part of the copyright of the content they publish''. By uploading pictures, users allow platforms to make their content public for the rest of users. Therefore, Muñoz suggests us to fully read said terms and conditions not just to take care of the copyright, but also to ''preserve our privacy as users of these platform''.
But what about the images provided by Google?
Google allows us to reach any picture uploaded to the Internet, but as stated by Muñoz, it's even possible to sort these images by ''free to use, share or modify'' in the advanced search mode. Muñoz however recommends that ''the best way to download these images is not through the Google Images search, but through the website hosting them. There we can check if they are free to use or if there are restrictions to them''.
There are also websites like Flickr and Pixabay hosting free pictures, but you need to check the details of every picture to make sure if they are free to use or you need to credit the author instead.