Email có thể được sử dụng để tracking thông tin user: thời điểm, địa điểm, những bức ảnh bạn chụp…
“Amazon has been using them a lot, Facebook has been using them. Facebook is the number one tracker besides MailChimp.” When Facebook sends you an email notifying you about new activity on your account, “it opens an app in background, and now Facebook knows where you are, the device you’re using, the last picture you’ve taken—they get everything.”
Phương thức để ngăn chặn email tracking:
A host of anti-tracking services have sprung up to combat the rising tide of inbox tracers—from Ugly Mail, to PixelBlock, to Senders. Ugly Mail notifies you when an email is carrying a tracking pixel, and PixelBlock prevents it from opening.
“The only surefire solution right now is to block images by default.” That is, turn on image-blocking in your email client, so you can’t receive any images at all.
On PC Chrome browser, using free Chrome extension called Ugly Mail. If there is a tracker inside emails you are reviving, then you will be bale to see that without actually opening the email. And as a bonus point, it automatically blocks the email tracking when you have installed it in your browser.
The whole story:
Both Amazon and Facebook “deeplink all of the clickable links within the email to trigger actions on their app running on your device,” Seroussi says. “Depending on permissions set by the user, Facebook will have access to almost everything from Camera Roll, location, and many other logs that are hidden. But even if a user has disabled location permission on his device, email tracking will bypass this restriction and still provide Facebook with the user’s location.”
“I JUST CAME across this email,” began the message, a long overdue reply. But I knew the sender was lying. He’d opened my email nearly six months ago. On a Mac. In Palo Alto. At night.
I knew this because I was running the email tracking service Streak, which notified me as soon as my message had been opened. It told me where, when, and on what kind of device it was read. With Streak enabled, I felt like an inside trader whenever I glanced at my inbox, privy to details that gave me maybe a little too much information. And I certainly wasn’t alone.
There are some 269 billion emails sent and received daily. That’s roughly 35 emails for every person on the planet, every day. Over 40 percent of those emails are tracked, according to a study published last June by OMC, an “email intelligence” company that also builds anti-tracking tools.
The tech is pretty simple. Tracking clients embed a line of code in the body of an email—usually in a 1×1 pixel image, so tiny it’s invisible, but also in elements like hyperlinks and custom fonts. When a recipient opens the email, the tracking client recognizes that pixel has been downloaded, as well as where and on what device. Newsletter services, marketers, and advertisers have used the technique for years, to collect data about their open rates; major tech companies like Facebook and Twitter followed suit in their ongoing quest to profile and predict our behavior online.
But lately, a surprising—and growing—number of tracked emails are being sent not from corporations, but acquaintances. “We have been in touch with users that were tracked by their spouses, business partners, competitors,” says Florian Seroussi, the founder of OMC. “It’s the wild, wild west out there.”
That’s partly to do with spam. “Competent spammers will track any activity on your email because they tend to buy entire lists of addresses and will actively try to rule out spam traps or unused emails,” says Andrei Afloarei, a spam researcher with Bitdefender. “If you click on any link in one of their messages they will know your address is being used and might actually cause them to send more spam your way.”