JavaScript Attack Can Be Used to Spy on Browser Tabs

Besides the Amazon leak, here’s some more troubling news. Researchers demonstrated a side-channel JavaScript attack that made it possible for them to spy on your other browser tabs. And even Tor is susceptible.
This information can be used to target adverts at you based on your interests, or otherwise work out the kind of stuff you’re into and collect it in safe-keeping for future reference. The technique is described in a paper recently distributed through ArXiv called “Robust Website Fingerprinting Through the Cache Occupancy Channel.”
It doesn’t sound like there’s a fix for this at the moment.