In Wiki Loves Public Art we got some experience with non free artworks. Although in Spain exists freedom of panorama, some artworks may be indoors were FoP does not apply. We marked all doubtful listed artworks with a parameter showing an icon or a placeholder with a notice like "we think you can not upload a free photo of this artwork" and they were excluded from contest.

Example: https://ca.wikipedia.org/wiki/Llista_de_l%27art_p%C3%BAblic_de_Barcelona

Vicenç

Date: Tue, 20 Aug 2013 20:35:49 +0300
From: pavlo.shevelo@gmail.com
To: wikilovesmonuments@lists.wikimedia.org
Subject: Re: [Wiki Loves Monuments] WLM in Greece

Hi, I'm from Ukraine (WMUA) and we also "enjoy"

> very complicated and unfriendly law for photos of monuments and heritage

so called "lack of panorama freedom" so we (perhaps not me personally but still) are very much interested in experience interchange how to handle that tough and nasty matters.

Regards,
Pavlo