Can people add additional terms to CC license?

[Halie0201]

Hello,

I found a website licensing images under CC BY-NC-ND license.

https://www.npg.org.uk/collections/sear ... &x=75&y=11
There are three licenses on the web: Professional, Academic, and Creative Commons. In this case, if I want to use this image in the classroom, non-commercial book or film, I have to buy a license according to the webste.
But I noticed that, according to CC BY NC ND license,

No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

And when I download the image, I will check the box say that "To download an image you must read and agree to the full agreement terms and conditions. This is a required field."
It proves that the CC license is the only and full license I should comply when I download the image from there. So I understand that as long as I follow the CC BY NC ND license, I can use it in the classroom, non-commercial book or film, too. Because the CC license can be the full license and I don't need to follow other license terms.
I am not sure if this is correct or not.

[AndyJ]

Hi Halie,

Yes you are right, Creative Commons licences are standardised licences which are not supposed to be altered or adapted with special conditions. If a user wishes to apply special licence terms they should devise their own specific licence, as for instance the UK government has done with the Open Govenrment Licence. If you feel strongly about this, you have the option of reporting the National Portrait Gallery to Creative Commons.

Of course a CC licence presupposes that copyright exists in the work in the first place. The only reason the NPG is taking this route in the first place is that their copyright claims were challenged a few years ago by the Wikimedia Foundation, and when it looked likely that the US courts would rule against the NPG's copyright claims, they settled with Wikimedia and introduced this system whereby only users requiring higher resolution images needed to pay a fee. The introduction of the modified CC licence seems to be a new, and unwelcome, development which imposes uncalled for restrictions on users wishing to access works of art which are free of copyright and owned by the public.

For an expanded discussion of the position over copyright under UK law, see this blog posting by IP barrister Francis Davey. Mr Davey then went on to write a thesis on the subject in which he concluded, in contrast to his earlier comments, that "The National Portrait Gallery's photographs would be unlikely to attract European copyright protection"
(Francis Davey After the National Portrait Gallery: Can there be copyright in exact photographic copies? University of Strathclyde 26 Aug 2011)