"The shots heard around the world"

Recent mass shootings in the US and elsewhere affect me in a particular way: My parents grew up in Nazi then Soviet occupied Pest, on the east shore of the Danube overlooked by the Buda Castle (dark green below), from which guns fired down streets perpendicular to the river (grey at right below), so residents literally ran the gauntlet across those streets, and friends of my parents lost a babe in arms from a stray bullet; my parents thus emigrated just before my birth to give me a better life, but that included six months in Algiers during a revolution where I too witnessed two fatalities early 1961.

Maps are forever...

... or they are Man's best friend. I'm a big fan of the British Library, not only because it's next to Kings Cross station I alight when coming to London often (or rarely hop onto the Eurostar at nearby St Pancras to Bruxelles or Paris) - bl.uk has an amazing array of old maps, which they just finished georeferencing through a significant effort in crowd-sourcing (the 21st. c. variant of volunteering).