h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I can easily understand why at the moment photos are limited to those that are taken by a researcher themselves, or by a community artist/photographer.
It would be too complicated to use photos that had any limitation of use on them.
But couldn't h2g2 use photos that are offered with no restrictions elsewhere - either by photographers themselves, or by larger organisations who choose to let their photos be used elsewhere with no restrictions.

When someone signs up to h2g2, they agree that they will allow the BBC to use the content they create. Without the photographer or writer signing up to that agreement, it's difficult for the BBC to use it. While some other organisation might have a policy to allow further reproduction of their material, the BBC have no control over when that organisation might choose to change its policy - which could leave the BBC in a precarious legal position.

There have been situations before where people who haven't signed up to the site have agreed that a diagram they made or a picture could be used, but it can't be used unless they agree to the terms and conditions by signing up to the site. It's frustrating sometimes, but that's the way it is, unfortunately.

if you change the rules about how you let someone use their information then that person still only has to obey the previous licence, unless it was agreed that they had to obey any change.

For example, we give a non-exclusive right to our work so the beeb can use it

The beeb cant change it to an exclusive policy and yank our work off the web.
Nor can we change our agreement and take our work off hootoo.