These (from 19-21 of the PDF at https://storage.courtlistener.com/recap/gov.uscourts.ohsd.28...) appear to form the entire (?) basis for alleging Matienzo's involvement:

VI. The Individuals Behind Anna’s Archive and their Conspiracy to Illegally Target
and Harm OCLC.

107. After Anna’s Archive identified itself as the perpetrator of the hacking attacks, OCLC set out to identify the individuals behind Anna’s Archive.

108. Defendant Maria Dolores Anasztasia Matienzo is software engineer at Tome and former catalog librarian at a direct competitor of OCLC.

109. On information and belief, in addition to her extensive online presence, she has a GitHub (a software code hosting platform) account called, “anarchivist,” and she developed a repository for a python module for interacting with OCLC’s WorldCat® Affiliate web services.

110. On her personal blog, Matienzo describes herself as an “archivist.”

111. Matienzo has publicly stated that libraries and archives should be open and publicly available.

112. On information and belief, Matienzo has a deep understanding of OCLC’s WorldCat® and software coding, which she has utilized to support Anna’s Archive, along with her experience at an OCLC competitor.

113. On information and belief, the other individuals behind Anna’s Archive, Defendants John Does #1–20, reside in various foreign countries, including Israel and Brazil.

114. On information and belief, Defendants John Does #1–20 have experience with data scraping, with online piracy, with software development, at OCLC’s competitors, etc., which they use to support Anna’s Archive, including through the attacks on OCLC.

115. In a blog post, Anna’s Archive had previously stated, “we would love to quit our jobs in finance and tech.”15

116. On information and belief, the individual defendants’ professional profiles fit the blog post’s “jobs in finance and tech” description.

117. Upon information and belief, each individual defendant has used their library cataloging, software, and/or technological skills to create Anna’s Archive, willfully violate international, federal, and state law, directly target OCLC, hack WorldCat.org, and distribute WorldCat® data, in order to facilitate the piracy of protected works.

118. As set forth in Anna’s Archive’s blog, Defendants have acted, and continue to act, in concert in furtherance of a plan or agreement to tortiously interfere with OCLC’s contractual and prospective business relationships in relation to OCLC’s WorldCat® service, hack WorldCat.org and OCLC’s servers, and trespass upon and convert OCLC’s property, including its WorldCat® data and servers.

119. As a result of Defendants’ plans, OCLC will face difficulties meeting its obligations under the WorldCat®’s Rights and Responsibilities agreement and its service agreements with customers.

120. Upon information and belief, as a result of Defendants’ plan, one or more OCLC WorldCat® customers or potential WorldCat® customers has or will opt to forego OCLC services, including WorldCat®.

121. Upon information and belief, Defendants’ coordinated and intentional predatory and tortious targeting of OCLC’s WorldCat® data is willful and malicious, and it has caused, and will continue to cause, significant injury to WorldCat® and OCLC in Ohio and elsewhere, as discussed in this Complaint