Question about using photos....

Is it legal to use photos from various sources if you cite the source, i.e. "photo courtesy thatsite.com"? Does anyone have any links to articles on this topic? Thanks!

Always contact the copyright holder if possible before using another person's images. Some images are meant to be public domain and some are not.

So there is no blanket rule on this sort of thing? Like saying I use your image in exchange for citing the source?

Always ask permission first. It's a matter of a) copyright laws and b) plain common sense.

The whole "courtesy of" thing implies that permission was granted from the copyright holder to use the image.