If you use chrome you are probably aware of the "Incognito Window" function. This essentially opens a new browser window, not signed into anything, and without any local history stored during use. This can be a great countermeasure if you are using a public computer like a library, to check your social media or the like. Unfortunately, Incognito mode is not 100% history-free, as advertised.
In all modern websites there are many pieces of data handed to the user's browser for use both at that moment, and for future use if necessary(session storage). This session data is stored on the user's computer for quick and easy retrieval later, should you visit the page again. And while incognito saves that value for your current session, and when you open a new incognito window, this information seems to disappear... it doesn't. To the average user, yes, that data is gone, but if your laptop or computer is stolen, a seasoned hacker can still easily access all of your incognito browsing history. In fact, chrome tells you this right on the main page when you activate Incognito mode...
Your activity might still be visible to:
Many people believe they are both completely anonymous and invisible when using incognito mode... This couldn't be farther from the truth either, and for that to work, you need a VPN, or something like in our secure browsing article on TOR browsing.