diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..0131699
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 s3lph
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index 7d93dba..1c9f20e 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,13 @@
 
 Generate a map similar to https://www.ccc.de/regional from Wikidata and the doku.ccc.de Semantic MediaWiki data.
 
+## TL;DR
+
+```
+pip3 install -r requirements.txt
+./generate_map.py --update-erfalist
+```
+
 ![Map as generated by this tool](map.readme.png)
 
 ## Installation
@@ -45,6 +52,14 @@ A run without cache takes some time as it fetches all data from their sources:
 
 **Use the cache at least for the country and state borders.  Otherwise, Wikidata will start rate limiting pretty quickly.** 
 
-## Fonts
+## License
+
+Unless otherwise noted, the contents of this repository are licensed under the MIT License (See LICENSE).
+
+### Fonts
 
 The font contained in `style/concertone-regular.ttf` was created by Johan Kallas (johankallas@gmail.com) and is licensed unter the terms of the SIL Open Font License v1.10.
+
+### Geoshape Data
+
+The geoshape data contained in `cache.example` is in the public domain.
diff --git a/generate_map.py b/generate_map.py
index ac2a235..e8fe35e 100755
--- a/generate_map.py
+++ b/generate_map.py
@@ -1,4 +1,6 @@
 #!/usr/bin/env python3
+#
+# https://git.kabelsalat.ch/s3lph/erfamap
 
 import os
 import urllib.request
@@ -34,10 +36,6 @@ class CachePaths:
         self.chaostreff_info = os.path.join(path, 'chaostreff-info.json')
 
 
-#BOUNDING_BOX = [(4.27775, 46.7482713), (19.2403594, 54.9833021)]
-# --bbox 4.27775 46.7482713 19.2403594 54.9833021
-
-
 ERFA_URL = 'https://doku.ccc.de/Spezial:Semantische_Suche/format%3Djson/limit%3D50/link%3Dall/headers%3Dshow/searchlabel%3DJSON/class%3Dsortable-20wikitable-20smwtable/sort%3D/order%3Dasc/offset%3D0/-5B-5BKategorie:Erfa-2DKreise-5D-5D-20-5B-5BChaostreff-2DActive::wahr-5D-5D/-3FChaostreff-2DCity/-3FChaostreff-2DPhysical-2DAddress/-3FChaostreff-2DPhysical-2DHousenumber/-3FChaostreff-2DPhysical-2DPostcode/-3FChaostreff-2DPhysical-2DCity/-3FChaostreff-2DCountry/mainlabel%3D/prettyprint%3Dtrue/unescape%3Dtrue'
 
 CHAOSTREFF_URL = 'https://doku.ccc.de/Spezial:Semantische_Suche/format%3Djson/limit%3D50/link%3Dall/headers%3Dshow/searchlabel%3DJSON/class%3Dsortable-20wikitable-20smwtable/sort%3D/order%3Dasc/offset%3D0/-5B-5BKategorie:Chaostreffs-5D-5D-20-5B-5BChaostreff-2DActive::wahr-5D-5D/-3FChaostreff-2DCity/-3FChaostreff-2DPhysical-2DAddress/-3FChaostreff-2DPhysical-2DHousenumber/-3FChaostreff-2DPhysical-2DPostcode/-3FChaostreff-2DPhysical-2DCity/-3FChaostreff-2DCountry/mainlabel%3D/prettyprint%3Dtrue/unescape%3Dtrue'
@@ -74,6 +72,9 @@ def fetch_geoshapes(target, shape_urls):
         try:
             with urllib.request.urlopen(url) as resp:
                 shape = json.load(resp)
+            if not shape.get('license', 'proprietary').startswith('CC0-'):
+                # Only include public domain data
+                continue
             candidates.setdefault(item, []).append(shape)
         except urllib.error.HTTPError as e:
             print(e)