
DoubleClick Tries to Force Hand into Cookie Jar (1997) - jpelecanos
https://www.wired.com/1997/03/doubleclick-tries-to-force-hand-into-cookie-jar/
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jmisavage
AdTech firms have been tracking you for a long time and in some pretty
ingenious ways. One of the most recent was using the Battery Status API. Just
imagine if they focused their efforts on something useful.

As a side note DoubleClick has been own by Google since 2007.

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cdolan
Can you share more details about the battery status API tracking? Would love
to see how that correlates to a unique user.

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yathern
It's all about adding bits of information to improve confidence in tracking
users across pages.

Lets assume that in page visits <10 minutes apart, a users battery won't
change by more than 10%.

So say I go to volvo.com and then reddit.com - and my battery changes from 10%
to 8%. When I request reddit.com - the user is clearly not a visitor who has
had >20% battery. We also know the resolution of the phone. We know the user
agent. And many other factors. Combining all of these means that you approach
100% certainty that it's the same user. No information on it's own is
identifiable - but by combining enough sources - no two machines or phones are
identical (at least that's what advertisers hope)

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npsimons
This is scarily close to how intelligence agencies infer information. If you
ever wonder why government is so clandestine about even unclassified bits of
data, consider how they could be used when combined. As someone else said,
just imagine if they focused their efforts on something useful. Intelligence
agencies basically _are_ focusing on "something useful".

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yathern
I see the relation - but it's also how nearly all information is gathered and
infered - even at a human level. You take incomplete information, look at the
landscape, and try to fill in the blanks.

A friend you're meeting tells you he's in the starbucks with a red shirt.
That's not enough information to know his exact coordinates. But you combine
and infer - you know how many starbucks there are in the vicinity, and which
one he's likely to be at. You know he's in a red shirt - but there's several
people. Luckily you already know his height well enough to filter out false
positives within milliseconds.

The method I don't find intrinsically scary - but perhaps the scale and depth
at which it happens, and for what motives.

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jeff6845
On mobile devices, I can see this API for decent tracking. However, for
laptops, it seems easy to have the laptop fully charged and plugged in to
defeat it as this is probably a very common state.

It would be fun to alter the API output to randomize the battery data. Even
have it be off power, and slowly climb in charge.

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yuhong
I mentioned it on my thread with BrendanEich:
[https://twitter.com/yuhong2/status/912757701163106304](https://twitter.com/yuhong2/status/912757701163106304)

