Not necessarily black or white. The background can be green, yellow - whatever, as long as it is a plain, solid color and there are no shadows or reflections.
More info: http://blog.dreamstime.com/2011/07/27/isolated-in-stock-language_art35755

Cheers,
Attila

Hi Froogz, I was the one who "censored" you, when you've started attacking other users. Do you remember? Right when you finished questioning our honesty as an agency, you started pointing fingers at other users.
Oh, wait, that's not called "censoring", it's called "moderating". We don't allow anybody pointing fingers or attacking other users. It's simple common sense on any forum, not just on Dreamstime. If you had anything to complain about other users, you should have contacted us by email, not like you did - starting a thread AND writing a blog about it, like you own the absolute truth. That really was not a grown up behaviour.

You were allowed to criticize us, and that thread is still live right now. You had the right to an opinion. But for sure you will not be allowed to attack other users.

Regarding the subject of your thread, if we had to accept only original concepts, there would have been less than 100.000 photos on all agencies. Actually, the photographer you think that was copied clearly said once that he finds his inspiration in other stock sites. So, you don't know for sure if it was an original idea. And regarding keywords, the same photographer set up a FREE keywording tool, to help other contributors in keywording their images. This should have been enough for you to understand his position on inspiration. Oh, and I'm pretty sure he doesn't need any protection supplied by you

It seems to me that you should concern more about yourself and your photos, instead of searching around flaming subjects on public forums.