It's against the law to repost the entire content of newspaper articles to this website.
The court decided in LA Times v. Free Republic that entire copies of a copyrighted work could not be reproduced on a website under Fair Use.
Excerpting article and linking to articles in the archive is still considered Fair Use.
Translations, like those posted by MB Translations are a gray area. Generally, copyright belongs to the original author, but there are fair use exceptions.
Nonprofits and noncommerical uses are more protected under Fair Use than commercial uses. English common law focused primarily on the right to copy for commercial purposes. Infringment is concerned primarily with the way it affects the copyright holder's ability to make money from from work.
It's possible that a translation of something that's not "artistic" and more "factual" in a noncommerical nonprofit website like Indymedia is considered Fair Use because its goal is to increase the understanding of society. These foreign language works, not being otherwise translated, have little commercial presence.
Translations also potentially violate aspects of the Berne Convention.
Another exception to the copyright law may be given to archives, like Archive.org. Again, it's a gray area, as noted in this article:
Additionally, on the Left, there is an informal tradition of allowing radio/audio recorders to record and disseminate public speeches. These are owned by the speaker, legally, but they almost always allow the various recorders to redistribute the material. (Names that come to mind are Democracy U, Justice Vision, Voices for Global Justice, and LA Sound Posse.)
Furthermore, numerous articles and books from various left tendencies have been archived on the internet, without incident. Examples: Anarchy Archives, Infoshop Archives, and the Marxists Internet Archive.
A striking departure from this tendency occurred in 2014 when one organization that translated Marx and Engels, Lawrence and Wishart, told The Marxists Internet Archive to stop republishing copies of L&W translations of Marx and Engels Collected Works.
Additionally, ongoing publications like Z Magazine and Monthly Review and others do not give their articles for free. They sell access to their archives, and given the realities of publishing, it's necessary.
There are other issues not covered here, like photos, audio recordings of material from KPFK, and PDF documents.
The author of these notes is not an attorney, and this article is not to be considered legal advice.