That is really nice from you.
Unfortunately, many people steal art without even knowing that they are stealing, they just want to share, like you, the beautiful pictures they found on the web. It's important to me to raise awareness towards copyrights respects as I'm earning my life with my art, but of course I can understand mistakes, ignorance etc.
Next time, it would be nice to directly contact the artist and ask for permission to use his/her work.
xx