I recently edited a question Brick Wall: Searching for Grandfather - C&EI Railroad Employee in 1948 - who the heck was he? to remove the name of an individual that might still be alive, to bring it in line with our faq which states that we don't allow questions about locating identifiable living individuals.
Do we need a consensus on the criteria by which we judge that an individual might be living? In the US, I believe there's a 70-year restriction on access e.g. to census data to protect the privacy of the living. In the UK, there's a 100-year rule. No doubt elsewhere there are other relevant periods of time.