--- a/Allura/allura/model/auth.py
+++ b/Allura/allura/model/auth.py
@@ -297,7 +297,7 @@
 
     @property
     def activity_name(self):
-        return self.username
+        return self.display_name or self.username
 
     def get_pref(self, pref_name):
         return plugin.UserPreferencesProvider.get().get_pref(self, pref_name)