NearMap is an Australian aerial imagery and location based media company that (amongst other things) creates high resolution aerial imagery of Australian cities and surrounding areas.
Nearmap imagery was used for OSM tracing from 2009 up until June 17, 2011. Many objects currently in OSM are still sourced from Nearmap imagery.
In June 2011, Ben Last of NearMap clarified that the new OpenStreetMap license would not be compatible with the CC-BY-SA style license under which data can be derived from NearMap PhotoMaps.
Use of Nearmap aerial imagery as a source for OpenStreetMap was permitted by NearMap until 17 June 2011, and Nearmap agreed that existing derived data could remain in the OpenStreetMap database post-licence change.
In December 2012 Nearmap removed the remaining no-charge access options for Nearmap imagery.
Post 2011 use
Occasionally customers of Nearmap make edits to OSM based on their imagery, until these contributors can prove the legality of this, edits which use Nearmap aren't permitted.