I have been warned by a friend from the OSM community that slippymap is in breach of the OSM copyright, for reusing the map without showing the attribution required by OSM. Furthermore, it is being reused from slippymap by 3rd parts, including the Environment Secretary of Azores, consequently not showing the attribution (as it's not shown in slippymap in first place)
I'm not sure if this is the proper place to fill a bug about slippymap, but I've seen some have already filled in the past, so here it is. If it is not the proper place, I hope someone can provide some advice about where to post this bug.
Steps to Reproduce:
Just go to http://tiles.wmflabs.org/osm/slippymap.html ant check, there is no attribution as required by OSM
Attribution is lacking, the tool is in breach of OSM licensing terms
Attribution to OSM is properly shown, as required by licensing terms