The French nationality law itself, strongly secular, forbids any statistics or lists based on ethnic or religious membership.
In 2006, for example, the Conseil représentatif des institutions juives de France (CRIF) sought to constitute a sample of individuals for the purposes of a survey on Jewish opinions by sorting through last names. This was deemed a violation of the letter and spirit of French & European law concerning the automatic treatment of private information (decision).
Tagging biographies of living people in en.wp with the category "French Jews" would seem to be likewise a violation of privacy. French law is quite clear on this: it carries with it a penalty of €300,000 and/or 5 years imprisonment:
Le fait, hors les cas prévus par la loi, de mettre ou de conserver en mémoire informatisée, sans le consentement exprès de l’intéressé, des données à caractère personnel qui, directement ou indirectement, font apparaître les origines raciales ou ethniques, les opinions politiques, philosophiques ou religieuses, ou les appartenances syndicales des personnes, ou qui sont relatives à la santé ou à l’orientation ou à l'identité sexuelle de celles-ci, est puni de cinq ans d’emprisonnement et de 300 000 € d’amende.
Moreover, it would seem that Wikimedia France could well be implicated in this matter:
Le fait pour un fournisseur de services de communications électroniques de ne pas procéder à la notification d'une violation de données à caractère personnel à la Commission nationale de l'informatique et des libertés ou à l'intéressé, en méconnaissance des dispositions du II de l'article 34 bis de la loi n° 78-17 du 6 janvier 1978, est puni de cinq ans d'emprisonnement et de 300 000 € d'amende.
Now, of course, the question of the physical location of the WMF servers has historically been a determining concern. Since the servers are in Virginia, Amsterdam, Singapore, etc. it is not clear that individuals whose privacy has been violated in this way would have legal recourse.
I added this comment to a discussion "Arbitration Case on World War II topics" where it was deemed to be "off topic". The thread was locked and buried (presumably due to unrelated criticism of one of the administrators of the site).
Does anybody think this question would be better raised on the Wikimedia-L listserve? Personally, I suspect that this would only lead to further retaliatory action against me for pointing out governance problems at en.wp.
Does anyone here have any knowledge of previous discussions on this question? So far, I've only found a failed 2005 AfD of "List of French Jews" and no comment whatsoever on the ad-hoc category talk page.