You've got to be kidding me! Lols. You don't think Mozilla knows how their browser works? These guys are very clever. I'll tell you something. The browser history is mirrored and stored elsewhere. The default for that mirror is not 180, it goes to that number each and every time you use the "private browser" feature. The reason? Information gathering has become quite an industry. How do you think Mozilla supports itself? If it didn't sell more of your information they wouldn't make as much money. They really fool a lot of people with this crap. Think about it. Why wouldn't they more clear about this? Set your history to 7 days just to discover that's a minimum. So 180 days is stored because you went "private". Don't believe me? Test it for yourself. It's cryptic for a reason and trust me it's not left over code just lying around. Oh... and another thing. It also stores your history from Internet Explorer too. Isn't that nifty? Noticed some C:/ files in there too. lols