Pirate sites often refer to themselves as "open access." While in a literal sense, they are opening access to copyrighted works, they are not "Open Access" within the meaning of that term by scholarly publishers, researchers, scholars, and librarians. Scholarly OA is a well-established method of making scholarly works freely available to all readers worldwide without paywalls and operates completely within the scope of copyright law. There are some significant obstacles to widespread adoption of the OA model, such as article processing charges that authors (or their funders) must pay that are often thousands of dollars.
Read more about scholarly OA here.
Other types of free access to scholarly literature may use the same or similar terminology but operates outside of national and international copyright laws and licensing agreements; these are not Open Access. Some examples are:
Guerilla Open Access Manifesto
In this 2008 document, Aaron Swartz writes, "Those with access to these resources — students, librarians, scientists — you have been given a privilege. You get to feed at this banquet of knowledge while the rest of the world is locked out. But you need not — indeed, morally, you cannot — keep this privilege for yourselves. You have a duty to share it with the world. And you have: trading passwords with colleagues, filling download requests for friends."
This suggestion violates not on copyright and other federal laws, but also Georgetown University's information security policies and the library's licensing agreements with publishers and database providers.
Sci-Hub
From the Sci-Hub website:
no copyright
We advocate for cancellation of intellectual property, or copyright laws, for scientific and educational resources.
Copyright laws render the operation of most online libraries illegal. Hence many people are deprived from knowledge, while at the same time allowing rightholders to have a huge benefits from this. The copyright fosters increase of both informational and economical inequality.
open access
The Sci-Hub project supports Open Access movement in science. Research should be published in open access, i.e. be free to read.
The Open Access is a new and advanced form of scientific communication, which is going to replace outdated subscription models. We stand against unfair gain that publishers collect by creating limits to knowledge distribution.
Open access is not the same as "cancellation of ... copyright laws." Scholarly open access respects author's rights and copyright laws while making information widely available without cost to the reader.