
Ask HN: How does Facebook know my Google searches? - brad0
I was doing some work on a side project earlier today and Googled &quot;pug&quot; for pug.js. Google returned results about dogs instead, so I clarified my search to pugjs and thought nothing more of it.<p>I&#x27;ve just logged into my Facebook account tonight and it has two suggested groups on the right hand side. &quot;Pug Crazy&quot; and &quot;Passionate about Pugs&quot;, both dog related.<p>How the hell has Facebook linked my Google searches to my Facebook account? I just mentioned it to some family that said they&#x27;ve experienced the same thing from searching a camping spot. Is it time to nuke all my accounts from orbit?<p>---<p>EDIT<p>I used two Chrome profiles with the following extensions:<p>dev - 1Password, Adblock Plus, Click&amp;Clean, Privacy Badger<p>personal - 1Password, Adblock Plus, Chrome Remote Desktop, Click&amp;Clean, cookies.txt, Privacy Badger, Save to Pocket
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brudgers
Several businesses paid Google to show you advertisements for canine pugs.
Note that Google did not collect revenue from the purchasers to show canine
pug advertising to _someone_. Google charged to show it to _you._

The advertisers spent the money and got the data and correlated it with all
the other data they have...including things like the fact you use Chrome and
have four specific extensions and which country you are in and probably your
ISP and the state of your microphone and whether you have a GPU to perform
WebGL and if so how fast it is and the round trip latency to some CDN and a
bunch of other stuff and all this anonomyzes you down to a market segment of
size = one.

Really smart people have been sitting around all day year in and year out for
decades figuring out how to track consumer behavior because there is big money
in it. It wasn't invented with the cookie two decades ago. The cookie was an
implementation detail of work credit card companies started two decades or
more prior.

Good luck.

~~~
brad0
I'm assuming you're referring to browser fingerprinting.

If you want to know how unique you are you can check EFF's Panopticlick
[https://panopticlick.eff.org/](https://panopticlick.eff.org/)

Next question: How does anyone guard against this? My canvas fingerprint is 12
bits of identifying info even though I have what I would consider to be a
fairly common MacBook Pro. Between this and my WebGL fingerprint (11 bits) I'm
most likely uniquely identifiable.

~~~
brudgers
IP addresses probably have three or four bits of entropy at best: home, work,
mobile, school, a few free wifi locations. Browser fingerprinting is an
alternative when the data isn't already available. I just riffed on it as an
example of the asymmetry of the information conflict between individual and
organizations armed with many many data centers.

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mtmail
My theory: one of the pug.js related websites had a Facebook like/share
button. Facebook took the hint that you're interested in something pug related
because it mis-classified the domain/page.

~~~
brad0
I use Privacy Badger on Chrome, which should block all social widgets by
default. I'd be surprised if this was the vector.

------
yitchelle
Just looking from outside the square, is it possible that the Facebook cookie
on your machine is interrogating the Google cookie or your browse history?

~~~
brad0
From memory I logged in to Facebook using my personal Chrome profile and I
searched for pug.js on my development Chrome profile.

I'm fairly sure I opened the pug search on my dev profile but it's possible I
opened it on my personal one by mistake.

Every time my chrome Profile window is closed it wipes all
cookies/history/local storage etc. using Click & Clean.
[https://chrome.google.com/webstore/detail/clickclean/ghgabhi...](https://chrome.google.com/webstore/detail/clickclean/ghgabhipcejejjmhhchfonmamedcbeod?hl=en)

Either way it seems Facebook is acquiring user data in a really creepy way.

