You’re probably sharing more than you think on Facebook

If you’re thinking about Facebook privacy right now, you’re probably thinking about Cambridge Analytica, which collected information about hundreds of thousands of Facebook users and tens of millions of their Facebook friends back in 2014, then sold that info to certain political campaigns.  Shady?  Very.  But collecting that kind of data wasn’t actually against Facebook’s policies at the time.

In a much less nefarious use of online data, I’ve been using Facebook as a tool for a family genealogy project.  In addition to tracking back my direct ancestors, I am (in a private, offline format) mapping out my various great-aunts and second cousins and half-cousins once removed.  As a category, these are “people my mom sends Christmas cards to; I might have met them but I don’t really know them.”  My goal here is mostly to be able to remember who they are the next time my mom talks about them.  I’m just collecting basic family tree data: where and when they were born, when they got married and to whom, and if they have any kids.

A lot of this information is available pretty directly on Facebook in people’s public profiles and public posts.  But there’s rather a lot of information available indirectly, too.  For instance, you might have set your birthday to friends-only, but if your timeline is public or friends-of-friends, that annual blast of “Happy Birthday!” posts gives away the day and month.  Add in a few “Happy 49th Birthday!”s, and the year is just basic math.  Another example of indirect sharing: setting your profile picture to a wedding photo to honor your anniversary.

Other potential information leaks:

• The “Family and Relationships” section of your Facebook profile.  Let’s say you’re linked to your niece Jane.  You have that info set to friends-only, but Jane doesn’t, so anyone looking at Jane’s page will know that you’re her aunt.

• Friends lists in general. Very often public, and useful for mapping relationships.

• Your current/past location.  Lots more data, from basic phone book stuff to marriage details, is discoverable from non-Facebook sources once you have a place.  (Fun fact: a great many U.S. counties have publicly searchable marriage license databases.)

• The classic oversharing relative.  I got the full name of one of my cousin’s kids from a hospital picture posted by her mom.

It’s not necessarily bad to have some of your information public, as long as you know about it.  I choose to keep my maiden name publicly visible on my Facebook profile because it helps me connect with friends from college. It’s the information you don’t realize is public that could be concerning.

[Note: I’m really not interested in hearing any more smug takes about how you quit / never joined Facebook; that’s nice, now go congratulate yourself somewhere else.]

Anyone else use Facebook for family history research?