Firefox privacy hint that has nothing to do with editingLately, every time I enter something in a textbox on the web, Firefox has been helpfully suggesting autocompletions for me. This was tolerable when it was my email address, but yesterday I was registering for a triathlon and darned if my browser didn’t already know all the answers. First it filled in my full street address and phone number, and when it followed up with my full credit card number, I knew something had to be done.
The concern I have about this is that I sometimes carry my laptop around while it’s running and I’m even logged in. If someone stole it, they could figure out my credit card number by opening Firefox and typing the digits 0 through 9 into a textbox until something that looked like a credit card number showed up in the autocomplete box. A lesser concern is that even if I secured the machine by logging out or locking my screen, if Firefox were storing my credit card number in any way, there would always be the possibility that that information could be extracted. Unlikely, but I’d rather not risk it.
The fix is simple: go to Firefox -> Preferences -> Privacy. Under History, choose “Use custom settings for history.” Uncheck “Remember search and form history.” To flush any form history that’s already stored, go to Tools -> Clear Recent History and then check “Search and form history” and click “Clear.”