Would also need to get a burner phone number w/ answering machine to take calls from 240 million grandmas, cheapskate businesses and cash-strapped public schools for any & all tech support questions until the end of time, because if there was an issue with system stability in any way whatsoever, or if the router went down or the printer stopped working, they'd assume it was the fault of 'the guy who changed everything'.
Linux is great & everything, but this sounds like a recipe for utter disaster, not a way to make an easy buck.
Think it's more of an allusion to lurking habits, active times, metadata, stuff not related to public posts. I'd imagine the average user has plenty of stuff they've browsed through that they wouldn't want their family / co-workers, etc. to know.