Google began to integrate custom content into
Google Maps . For example, if you enter the search query
restaurant stuttgart , Google will first display the information collected in the usual way (according to Google, containing data taken from its own search results, from local business owners and companies, and open sources such as Yellow Pages ).
After these links, below, you will see the newly created link See user-created content. By pressing it, the red bookmarks of objects will change to blue. True, it is not quite clear where these data come from, but it is likely that they are collected from public KML or KMZ files, and it is possible that from maps created using
Google My Maps .

via
Google Blogoscoped .