Social Media and Cloud storage facilities may well be stripping the data which proves you own your images.
The Embedded Metadata Initiative have tested various sites and facilities. They list which ones do what, and which preserve or strip your data.
NOTE: you will see that Facebook, Twitter and Flickr strip everything !!![button link=”http://embeddedmetadata.org/social-media-test-results.php” target=”_blank” color=”default” shape=”rounded” size=”small” align=”left”]Embedded Metadata Initiative » [/button]