I took pictures of the local St. Patrick's Day Parade and I'm wondering if I could sale these images as event images to the public. I was not asked or given permission to shoot these images of the very public and free parade through downtown streets, but I would like to provide these images of the parade for sale via my website. I understand anyone can take pictures of pretty much anything, but I want to sell these to the public that didn't have camera's or anyone that wants a picture of themself in the parade. Is this legal? Do I need permission? What about model releases?