Copyright Considerations
The photo and video content referenced at The Physics Classroom is not the property of The Physics Classroom. The photos belong to a collection of Flickr members who have chosen to use Flickr as a photo sharing website. As such, the rights to use any of this material on web pages, in PowerPoint presentations or in handouts cannot be granted by The Physics Classroom. All rights to ownership obviously belong to the Flickr member who owns the photo.
Many Flickr members have uploaded photos to their photostream and offer their work to the public under a Creative Commons license. A page on the Flickr website includes very understandable information regarding the various types of Creative Commons licenses. (View Creative Commons page.) Other Flickr members have copyrighted their photos and designated them as "All Rights Reserved." To determine the type of licensing associated with a Flickr photo, look under the Share this pull-down menu located above each photo on Flickr. The licensing associated with the photo is listed at the bottom of the menu.
All Flickr members have agreed at the time of account creation to abide by a set of Community Guidelines established by Flickr. One of the guidelines states:
Flickr makes it possible to post content hosted on Flickr to other web sites. However, pages on other web sites that display content hosted on flickr.com must provide a link from each photo or video back to its page on Flickr. This provides a way to get more information about the content and the photographer.
As teachers, we should model the appropriate use and display of content that is owned by others. And we should also be educated regarding that which we can and cannot do. There are many excellent articles present on the web about copyright laws, fair use policy, and creative common licensing. If uncertain about what you can and cannot do, or if simply in need of an education, consider the following resources:
http://www.chillingeffects.org/fairuse/faq.cgi
http://creativecommons.org/
If unsure as to whether it is appropriate or not to use a photo in a particular manner, the safest thing to do is to ask for permission. These requests should be directed towards the member of the individual photo that you wish to use. Contact information can usually be found on Flickr when visiting the member's Profile page within their photostream.