There are known knowns...
Some records have no geometry or a centroid of 0,0
Which the exception of Null Island these are records that need to be researched and updated. We use a default centroid of
0,0 to ensure as a way of tracking records that are still in need of editorial love and so that there is at least something to keep the more conversative GeoJSON parsers out there happy.
Some polygon records contain 'buffered point' geometry
Some records represent point data as polygon data, such as: https://whosonfirst.mapzen.com/spelunker/id/101873779, these records can be distinguished from actual geometries using the tag