The practice started with "Testing on the Toilet", which was a way to educate developers about unit-testing best practices. (This was back in 2005 or 2006, when Google very much had a cowboy-coding culture and a lot of products were just thrown over the wall for users to perpetually beta-test.) Then we got "Learning on the Loo", which is general life-hacking tips that started in 2010. I forget the official title of the Go series, but a friend and I were joking that it should be called "Going to the bathroom."
There's something slightly creepy about that... oO;