Beyond Classroom Walls does not collect or store any data about the users of the website. All Google related information used in the report is individually and repeatedly requested through Google's API for every session and is not saved anywhere.
The Google information collected is done on a need-to-know basis. This means that while permissions for scopes may be requested upon login, the actuall data itself is not accessed until the generation of the report.
All of the requested scopes are necessary for the generation of the report including the list of classes (read only), the list of topics (read only), class assignments (read only), class announcements (read only), student submissions (for the submission status and grade; read only), the class roster (for the student names to be included in the report and their emails to send the report to; read only), the list of guardian emails (to send the report to; read only), access to Google Sheets (to create the report), access to Google Docs (to create the report), access to Gmail (to email the report to the students and their guardians), and your Google profile (for your name to be attached on the report; read only).
All data collected is purged and deleted at the end of each session in order to protect the data and privacy of teachers using the site and the students whose details are published in the report. The report generated is stored directly in the user's Drive and is not saved elsewhere.