"We´ve seen" não quer dizer que eles tenham TODOS os documentos em poder deles e nem que estes 58 mil documentos sejam a totalidade do arquivo de Snowden. De qualquer forma:

http://www.huffingtonpost.com/2013/08/07/glenn-greenwald-edward-snowden-documents_n_3716424.html

"Greenwald told Reuters he does not believe the pro-transparency website WikiLeaks had obtained a package of documents from Snowden, and that only he and filmmaker Laura Poitras have complete archives of the leaked material.""