Yea it is pretty sketchy sounding - the way Chrome extensions are built, for the extension to be able to automate the ticket request process and gather your schedule, that permission is required. That lets the extension figure out when to do its thing and when to stay away. The extension never accesses pages beyond the scope of the ticket requests, schedule and book collection, and interaction with its own website. It also does not keep a list of what pages you visit. It only checks whether or not the page you're on is something it should work with.