Still, Google has SafeSearch, they have some conception of what one might not want to pop up unexpectedly. I know that that particular autocomplete was probably generated from history, but the browser could be more noob-friendly ... everybody starts from ignorance.

IIRC, incognito mode still picks up stuff that was done in the wide open - ie, the scenario from the comment above would still happen if the author went into incognito.

In addition to incognito mode, a "guest" mode that didn't pick up "regular" URL history would be useful for scenarios such as this.

I appreciate that incognito won't give someone my FB cookie, but I don't need them to know what sites I do visit.

I think he meant that his friend should use incognito mode when visiting "red..." site(s) ... Not that he should use incognito mode for his guests.