The portuguese Wikipedia only hosts non-free media under the restricted content exception (https://pt.wikipedia.org/wiki/Wikip%C3%A9dia:Conte%C3%BAdo_restrito). It only uses free media that is already at Wikimedia Commons.
Topic on Help talk:Extension:FileImporter
Hi, thanks for reaching out to us. We are curious, how did you manage to have no free files uploaded on ptwikipedia? Are there no files that are accidentally uploaded locally even-through they could be uploaded to Commons? We would be glad to see any links about that. Furthermore we're wondering what the motivation is for disabling the extension on ptwikipedia?
The community voted not to allow local file upload in 2006 (https://pt.wikipedia.org/wiki/Wikip%C3%A9dia:Vota%C3%A7%C3%B5es/Impedir_carregamento_de_imagens). I don't remember how this was implemented (I was a newbie at the time). We then allowed non-free content in 2009 (https://pt.wikipedia.org/wiki/Wikip%C3%A9dia:Vota%C3%A7%C3%B5es/Uso_Restrito_de_Conte%C3%BAdo_(fair-use)). Only users with more than 500 edits and registered more than 45 days ago can upload files (implemented through a filter: https://pt.wikipedia.org/wiki/Especial:Filtro_de_abusos/92). Our upload page also has clear instructions on how to proceed for free and non-free images (https://pt.wikipedia.org/wiki/Wikip%C3%A9dia:Carregar_ficheiro).
My only concern about having the extension active is that it might produce unnecessary work for others as the only files we have would not be allowed in Commons, so allowing the extension might allow the upload of non-free files that would have to be deleted.
Thank you very much for the explanation and the links – this is very interesting for us to know. About your concern that non-free files might get moved to Commons and produce extra work: This can be avoided easily by editing the configuration page of File-Importer. You can find it here: https://www.mediawiki.org/wiki/Extension:FileImporter/Data/pt.wikipedia Only files that have a template listed under the section "good" can be moved to Commons using the FileImporter. If you empty the list, you disallow to move any File to Wikimedia Commons.