I’ve discovered this exact vulnerability (it is really a vulnerability, since you even see friendships when both people have set their friends list to "only me"

I’ve discovered this exact vulnerability (it is really a vulnerability, since you even see friendships when both people have set their friends list to "only me") about a year ago and sent Facebook the description to their white hat program. Their response was more or less "won’t fix, no security issue". But it’s kind of funny to see a public blog post about this issue now, maybe this creates some pressure.