The are a number of sources you can use to locate images that are shared by creators under a creative commons license, which allows you the right to share, use, and build upon the work. Most will still require you acknowledge the creators, plus t's always a good idea anyway. Some search engines and systems like Google, YouTube, Wiki, etc. have a means to filter to Creative Commons or Pubic Domain works. However, be cautious since the individual that posted the content may not have been the creator with the right to do so.
