In accounting, gross profit, gross margin, sales profit, or credit sales is the difference between revenue and the cost of making a product or providing a service, before deducting overheads, payroll, taxation, and interest payments. This is different from operating profit (earnings before interest and taxes). Gross margin is the term normally used in the U.S., while gross profit is the more common usage in the UK and Australia.
None of the audio/visual content is hosted on this site. All media is embedded from other sites such as GoogleVideo, Wikipedia, YouTube etc. Therefore, this site has no control over the copyright issues of the streaming media.
All issues concerning copyright violations should be aimed at the sites hosting the material. This site does not host any of the streaming media and the owner has not uploaded any of the material to the video hosting servers. Anyone can find the same content on Google Video or YouTube by themselves.
The owner of this site cannot know which documentaries are in public domain, which has been uploaded to e.g. YouTube by the owner and which has been uploaded without permission. The copyright owner must contact the source if he wants his material off the Internet completely.