Something VERY strange happened to me tonight (using Firefox Developer Edition 109.0b3). I opened some piano sheet music I'd never seen, by a composer whose work I'd never played, and whose name I'd never, ever searched for online. As I often do, before trying the piece, I thought I'd see if people had already posted recordings of it. So in FF's address bar, I typed ''yt'' (my search keyword for YouTube), the composer's last name, and the piece's name in quotes. This YouTube search-results page appeared (see screenshot), with a list of recordings of that particular music by that composer... Normal, right? But when I right-clicked one of the results and clicked "Open Link in New Tab", the new tab told me I wasn't online. And indeed, I'd forgotten to turn my PC's WiFi adapter on. How is it possible FF had already cached all this info—including thumbnail images—based on a search I'd never done? Yes, I've looked up other composers' music... But does this mean FF has cached links related to every possible YouTube search for ''every'' piece by ''every'' composer?? Or is it some particularly creepy kind of privacy invasion? Tech note: In ''about:config'', I'd turned off ''network.prefetch-next'' but not ''network.predictor.enable-prefetch'' —could that have something to do with it? (Both are turned off now.) Thanks for your theories! Baffledly, A.