About the required permissions

"Access your data on all web sites"

• To be able to inspect all net requests so that they can be cancelled if needed. Only on http- and https-based URL addresses.

See code:

• https://github.com/gorhill/uBlock/search?q=%22chrome.webRequest%22&type=Code

"Access your tabs and browsing activity"

This is necessary to be able to:

• Create new tabs (when you click on a filter list, to see its content)
• To detect when a tab is added or removed:
• To update badge
• To flush from memory internal data structures
• To find out which tab is currently active (to fill popup menu with associated stats/settings)
• To be able to inject the element picker script
• To implement the popup-blocker

See code:

• chrome.tabs
• chrome.webNavigation