My mother is adopted and 23andMe and Ancestry have both provided me with a way of connecting with relatives as far apart as Canada and Australia. Before “revealing” my connection to them I’ve stated that in doing so I may reveal information about a shared ancestor that doesn’t put that person in the best light (my mum was the result of a short affair between a married man and a much younger woman at the end of World War 2). All have stated they are ok with this and in most cases had no contact to the ancestor involved anyway.