4 instead of 5 due to the last Permission the user has to grant the ad-on, while other iterations of same utility do not go past recognizing a tab, without gathering data. As per the pages detailed explanation of the permission, which stands at the top, quote, pursuant to the date of posting this review, and not at fault should they change the source code to avoid being, in lay term, a keylogger. : "Access your data for all websites

The extension could read the content of any web page you visit, as well as data you enter into those web pages, such as usernames and passwords.

Extensions requesting this permission might:

Read product and price information from a page to help find you the best price on items you're shopping for
Offer a password manager that reads and writes details of your username and password
Provide an ad blocker by reading the content of each web page you open to find and remove ad code."