From what the author explained, the router only sends an event to the server when it detects a user entering/exiting the network range and ignores everything else. There's nowhere on the article where he says he's permanently logging their WiFi activity.
Uh, yes you can. Couple weeks ago I reset my Windows 10 MSI laptop to a clean state using nothing but Windows itself. Somewhere in Windows 10 restore options there's an option to format your HD and install only Windows and nothing else. You don't need a DVD nor a USB drive. A click of a button and off you go.
There are lots of other beaches in Rio that could've been chosen to host the water events.
However, Rio wanted to have some sort of legacy after the olympic games, something to be proud of after spending so much money while people are suffering without health and security. So the governors chose Baía de Guanabara! It's poluted as fuck, but the intent was to cleanse it before the games and have it as the Olympic legacy.
As always, Brazil screwed it and the bay still is a shit hole. Hell, 2 days ago they found in the bay the body of a college student that was murdered nearby.
I made that mistake... https://bugzilla.redhat.com/show_bug.cgi?id=1562530