Copyright infringement is everywhere. A few years back, John Tehranian wrote a paper and then a book about just how much copyright infringement happens incidentally on a daily basis. The conclusion, from a back of the envelope estimate, is that an average person is likely liable for $4.544 billion in incidental infringement in a normal year. And that's not for sharing music and movies and what not, but just doing the normal everyday things you do.
National Portrait Gallery, London
With the news that the National Gallery in the UK has rescinded its long-standing "no photographs" rule, it appears that another opportunity for incidental and accidental infringement has been unleashed upon people in the UK. The National Gallery apparently realized that with everyone carrying a smartphone these days (and the fact that it offers free WiFi that it encourages patrons to use), it became kind of ridiculous to try to block photographs while encouraging people to use their phones to research the artwork they were looking at.
However, the original notice noted that "temporary" exhibits will still have restrictions on photography "for reasons of copyright." But, as IPKat notes above, it's not clear why that should only apply to the temporary exhibits, since many of the permanent exhibit works are still under copyright as well (though the museum itself might also hold the copyright on many of those works). Either way, IPKat wonders if merely including a piece of copyright-covered artwork in the background of a photo - such as a selfie - might lead to claims of infringement. While some countries have freedom of panorama laws that say it's okay to represent artistic works on public display, that apparently does not apply to paintings (though it does apply to sculptures).
In the end, it appears that while it may be unlikely to get sued over taking a selfie in the National Gallery, if you're the extra cautious type, you might want to avoid it for fear of yet another ridiculous copyright claim. As IPKat notes, the caselaw is at least ambiguous enough that if someone wanted to go after you for your selfie with fine art, you might be in trouble. That this end result is ridiculous and kind of stupid isn't really discussed in the piece, but seems rather obvious. Yes, it may be unlikely that a lawsuit will come out of it, but we've seen sillier lawsuits in the past, and I doubt it would surprise many if this new policy also results in a lawsuit down the road. Because that's just the way copyright works.