I was on a patio halfway up a tall building in the City in London, when a guy came out of the office I’d been consulting in and asked me if I wouldn’t mind moving a metre to the left as I was blocking the laser. Turned out that the cheapest and fastest way they’d found to set up a secure network with their sister office in another building a couple of hundred metres away was to set up a laser network. It just happened that line-of-sight was unfortunately obstructable by a six-foot-plus man eating a sandwich. This would have been 2012 / 2013?