In general everything created has an automatic copyright, with or without notice. It takes a written release to waive the copyright. It doesn't matter, how you got an image (or video), for free per e-mail, newsgroups, free from a website, even if you paid for a membership, you don't receive any rights to any of the sites images (or videos). So you're not allowed to post or use the image in any shape or form, unless for criticism or comedy ( fair use ).
So only photos or videos you have taken yourself are legally permitted to be posted here.
http://www.templetons.com/brad/copymyths.html