We know that textbooks can be prohibitively expensive. However, sharing pdfs of books, even if you're not making money from it, violates Canadian copyright law and SFU's policies.
Sharing copied books in Facebook groups or similar venues can result in legal action against the students involved and the University.
The new Fact Sheet on Sharing of Textbook pdfs outlines reasons why students should not participate in these groups, and provides links to resources for assistance if textbooks are unaffordable.
The SFU Copyright Office can answer any questions about this issue, or about copyright in general.
The Library can help you to reduce the cost of textbooks for your students.
Or consider adapting an Open Educational Resource (OER) or creating your own with a grant and project support from the Library.