Hello again,
Thanks for your input on this question! I'll add a few clarifications here to respond to points raised in the discussion so far. (As I'm subscribed in digest mode, I'll have to cut & paste.)
------- Nathan commented: "I'm not seeing an argument here for why Wikimedia should adhere to this law, if it is correctly stated by the OP. If France passed a law banning Internet-published photos of living people, how would we approach that law? If Germany barred publishing the place of birth, date of birth or religious preference of public figures? If the United States banned publishing the name of individuals accused of mass murder?" -------
Since I quoted it the law of 6 January 1978 in French, I'm pretty sure I got it right. ^^ On the other hand, I didn't translate or interpret the law in the context of current jurisprudence, so yes, maybe some more should be said...
It is legal in France to write an article about a notable person and mention their religious affiliation if they volunteer that information. What is *not* legal is to extract that information about them and add it to a database which lists Catholics -- as was done during the Vichy regime with punchcards. How exactly were Jewish people rounded up and sent off to concentration camps? (How did prefects go about locating Freemasons during the war?). While there was certainly some collaboration with the National Statistics Service (SNS) established during the Occupation, the most recent research suggests that this collaboration was not as significant as was once commonly assumed. The 1978 law was written before this research.
The fact that -- today on en.wp -- these religious categories are being overwhelmingly applied to Jews (and to a lesser degree to Freemasons) is certainly striking. (cf. the 862 members of Category:French Jews & the 21 members of the Category:French Christians).
Regarding the hypothetical situations you evoke (the first of which, of course, being particularly relevant since people in France do have a right to refuse the publication of their image (*unless* they are for some reason newsworthy))... I imagine that they will have to be dealt with on a case by case basis until national laws have been superseded by the new-wikiwiki-order of supranational arbitration.
------- Todd commented: "We should no more follow French censorship laws than we should follow Turkish ones. All editors are responsible for compliance with the laws in their jurisdiction." -------
First, the issue is privacy, not censorship. Nobody has prosecuted or will prosecute a newspaper for mentioning, for example, that Vincent Bolloré is Catholic (since he is open about that fact and does not object to having it reported). However, when the CRIF (a Jewish foundation) petitioned the CNIL for the right to compile a list of folks whose surnames were the same as the 150 most common donors to the foundation for the purposes of a survey they were told this would be a clear violation of the law. (https://www.legifrance.gouv.fr/affichCnil.do?oldAction=rechExpCnil&id=CN...)
What exists on en.wp is an ad-hoc categorization that does not guarantee the quality of sourcing. Anyone can add the category "French Jews" to 100s of living people's biographies with hotcat in a matter of minutes (with or without a source). Only the vigilance of the community is a safeguard against this sort of action. The state of the database at the moment is, again, telling: there are not 40 times more Jews in France than Christians nor are Freemasons likely to be 7 times more numerous than Christians. Yet this is precisely the *deformed* picture that emerges from this ad-hoc categorization system. As James and Yarsolav both observed, this is likely due to a problem of "bad editing" on en.wp. (I didn't mention it in my OP, but just as there are no such categories on French Wikipedia, Wikidata also does not seem to have categories based on the religion of living French people. Based on my limited research into the question, the ontology at Wikidata does indeed seem more respectful of personal privacy.)
Second, concerning legally responsibility: of course! The WMF only supplies the platform. The anonymous individuals who make use of it are legally responsible for their contributions. As a result, living people not wanting to have their religion included in a system of automatic list-generation would need to file a complaint against X (porter plainte contre X) in order to try to get the WMF to react to the violation of their privacy if they cannot convince the anonymous volunteer they contact in order to enforce their privacy rights (by deleting the ethnic/religious category from their Wikipedia entry).
Still, it could be persuasively argued that a foundation has a *duty of care* to its volunteers and should not facilitate their contributors (whose age they don't verify) falling afoul of their national laws. Simply excluding members of Category:BLP & Category:French Jews/Catholics/Muslims/Freemasons/etc. from the hidden Category "requiring diffusion" and adding them to the hidden Category "noindex" would go a long way towards protecting privacy rights (at least as far as google is concerned).
Finally -- again -- how useful are these automatically generated lists towards advancing the "freedom of knowledge" (as Nathan put it)? To repeat: these categories make it seem that there are/have been 40 times more notable Jewish people and five times more notable Muslims in France than notable Christians . This (derived) "knowledge" is patently false. Now, granted, the purpose of the automatically generated categories is not to come up with a comparative tally of noteworthy people; but I think what this tally shows is in itself revealing: Wikipedians are 40 times more likely to tag notable Jewish people as Jews and 5 times more likely to tag notable Muslims as Muslim than they are to tag notable Christians as Christians. This is worth thinking about for a minute...
Why would it be so hard to be humble and respect national laws by making it such that membership in the category would not be diffused concerning living people in countries where such lists are illegal? (As Yaroslav points out, there is no guarantee of the quality of the sourcing). En.wp might be wise to learn from the conservative approach to this question taken by fr.wp and wikidata.
I hope this helps to clarify the original post.
sashi
ps: *Correction*: Contrary to what I mistakenly wrote in my OP there are 96 members of the category French Muslims (not 0).