Privacy Alert Firefox -> file store.json

/home/user/.mozilla/firefox/cXXXqXnX.default/jetpack/jid1-F7XXXXXXX@jetpack/simple-storage/store.json

Even you deleting all the cache of Firefox, the file "store.json" still remains in the Firefox directory.

The file "store.json" contains all the sites you visit. Yes! All "those" sites. LOL.