An incident of map vandalism roiled the Internet last week. Users of several online services, including CitiBike, Foursquare and SnapChat, discovered that New York City had been relabelled “Jewtropolis” on the services’ maps: see coverage at Gizmodo, Mashable and TechCrunch. The problem was quickly traced to Mapbox, which provides maps to these services. Mapbox, understandably upset about the act of vandalism, soon figured out what the hell happened.

The problem was traced to OpenStreetMap, one of Mapbox’s data sources. On August 10 an OSM user renamed a number of New York landmarks, as well as New York itself, after a number of alt-right and neo-Nazi memes. The edits were quickly reverted and the user blocked—on OpenStreetMap. They nevertheless entered the Mapbox review pipeline, where they were, in fact, caught and flagged on the 16th, but a human editor mistakenly okayed the renaming of New York to Jewtropolis. A simple human error, but with a delayed fuse: the edit turned up on Mapbox’s public map two weeks later. When all hell broke loose on the 30th, the map was fixed within a few hours.

Vandalism of online maps isn’t a new thing: in 2015 Google ran into trouble when a series of juvenile map edits exposed the shortcomings of the Map Maker program’s moderation system and led to a temporary suspension of Map Maker (it closed for good in 2017) and an apology from Google. Anything involving user contributions needs a moderation system, and OpenStreetMap and Mapbox both have them. But moderation systems can and do still fail from time to time. (That’s a take on this incident that isn’t on Bill Morris’s list.)