Google founders Larry Page and Sergey Brin are recognized for their efforts at the conclusion of the Clinton Global Initiative in New York, September 22, 2006. Former US President Bill Clinton's annual event brings together world leaders from business, government and philanthropy to try to solve world issues. REUTERS/Chip East If you are a parent, Google wants to know. And, apparently, it can figure that out on its own and report your child-rearing status to its advertisers, according to Larry Kim founder and CTO of WordStream.

Google just added a "parental status" tab to its AdWords dashboard, allowing advertisers to use that as a criteria for ad campaigns, a WordStream data scientist has discovered. WordStream helps businesses manage their Google advertising campaigns, so it watches for every change that Google makes.

WordStream noticed that the parental status option went live to some advertisers late last week. Advertisers can choose between three settings "“Parent”, “Not a parent” and “Unknown."

This tab joins other demographic choices Google offers such as age and gender. Kim speculates that this is just the beginning:

This isn't just a great way for advertisers to reach increasingly granular audiences with their advertisements, it’s also a glimpse into the possibilities of what Google could offer advertisers in the future. They've already supported targeting by Age, Gender, Interests, and now Parental Status. Could we eventually see demographic subsets based on race? Sexual orientation? The more data advertisers have the better (for them), but is Google going too far?

Google insists that some things will say off limits and that users can opt out of this kind of tracking. It sent us this statement:

"Interest-based ads on our display network, including parental interests, have been around since 2009. We've made some changes to this in the Adwords interface for display campaigns. It uses the same system based on website visitation and users can edit or opt out of these ads on our Ads Settings page. As always, we don't allow ads to be targeted to sensitive categories like health, race or sexuality."

This situation brings to mind a recent social experiment done by Janet Vertesi, assistant professor of sociology at Princeton University.

She wanted to hide the fact that she was pregnant from Google, Facebook and other big data Internet companies. She had to go to great lengths to do it such as searching for pregnancy and baby care information only using an anonymous browser (Tor), routing the baby items bought on Amazon to a rented post office box, making no mention of her pregnancy on Facebook, and so on.

Knowing that a woman is pregnant (let alone a parent) is a marketing gold mine. A pregnant woman’s marketing data is worth 15 times as much as the average person’s, she said.

But to hide her prenatal status from the Internet took extreme commitment, carefully watching every detail of what she and her husband did online for months.

Most of us wouldn't be able to keep that up for years of parenthood. Plus, we'd like to share photos of our kids now and then, not hide them.

And that's, of course, why Google knows.

Here's the photo that Kim shared showing the new "parental status" in Google AdWords.