There’s a common saying among security specialists and privacy advocates stating that anything that is on the internet cannot be considered to be private. Private means that only the owner of the data has access to it. As an example, many of us use Google Drive to store backups of our data on the cloud. Because we use an account protected by a password (and usually by a 2-factor authentication mechanism), we may think it is private. However, it is not. Anybody working at Google who has access to the server could potentially gain access to our data.
The same happens with our online profiles (not only our social networks profiles). Those pictures that we only share with a selected group of close friends in Facebook or WhatsApp are stored somewhere in the cloud. Our pictures are stored in a remote server in some part of the world, and we don’t even know who has access to them.