That Http E-tag trick is already used by lot’s of the website to track peoples more you can read about this on Wikipedia https://en.wikipedia.org/wiki/HTTP_ETag#Tracking_using_ETags
The trick work without any use of:
- Flash, Java or other plugins
- Your IP address or user agent string
For a sample please visit
On that page type some text into the text box and store it, now restart your browser you can see your message is still here.
After disabling everything even in incognito mode you can see the message is still on the box after restarting the browser.
On that page ( https://lucb1e.com/rp/cookielesscookies/ ) you can see the right image there is a website hidden tracker inside the image e-tag.
Is the Tor browser can disable the tracker?
Yes, while trying this trick into all browsers the site is still able to track your data but this trick doesn’t work with the Tor browser you can see the results images below or you can try with yourself.
That is the most common reason Tor is still a security browser to visit any website 100% privately.