[...] l would know to turn privacy mode on when searching for things they shouldn't be searching for."
How does privacy mode actually work?
Unless it actually erases the space the files occupied then their content will remain retrievable until that disk free space is re-used. Even if they only store the files in ram - then the system swap file also needs to be cleaned afterwards.
What happens to the local storage used by web pages for what might be termed super-cookies? Some sites won't work if they are refused access to that store. IIRC in the past even if you asked for cookies to be deleted - that other local storage was persistent,
Biting the hand that feeds IT
