I guess, to nitpick, he means "any currently existing, freely accessible POI databases which support arbitrary polygon selection". Eg. most services which suppo

I guess, to nitpick, he means "any currently existing, freely accessible POI databases which support arbitrary polygon selection". Eg. most services which support "geospatial queries" (Flickr, Yelp, etc) only support MBR or simple geometry queries rather than true polygon intersects. Which I also misinterpreted but is also true (to my knowledge anyway). He's not saying it's impossible to set one up for yourself using PostGIS etc — if anything, that's his point. I agree with you that it's simple enough to set one up for yourself that the value offered by a service is minimal.