Let's be explicit. In the United States, the Computer Fraud and Abuse Act (CFAA) penalizes accessing protected computers without authorization. However, simply holding a might not be illegal if you never log in. But the moment you use that invitation to access the store, you cross a legal threshold.
If you access the site without an account or an invitation, you may be placed in "read-only" mode, which restricts your ability to view or download specific assets. ripperstore invitation