The art of having a sly wank unnoticed by the surrounding public, ideally practised on public transport, shopping malls or places of authority. Aimed at the gender/animal of your choice.
Going on Google Chrome or any browser that has a "no history recorded" mode, (called incognito mode on Chrome), and watching sexually explicit videos, usually to stop people from knowing that you've been watching it.
A mode in Google's new Chrome browser that does not record history, search entries or cookies to the user's computer. Downloaded files are still saved as normal.