Embassy of Ukraine requested OpenStreetMap to correct the status of Crimea
twitter.com
twitter.com
More details are on OpenStreetMap Ukraine blog & Twitter page.[2,3]
[0] https://facebook.com/ukraine.in.uk/posts/2444348232248682
[1] https://facebook.com/openstreetmapua/posts/779796859023276
TL;DR: OSM has marked Crimea as Russian territory with the reasoning that on the ground Russia has control over Crimea.