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:

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

"Manage your downloads"

• To be able to save your filters locally (in the "Your filters" tab in the dashboard)
• To be able to save your whitelist sites locally (in the "Whitelist" tab in the dashboard)
• To be able to back up all your data (from the "About" tab, just like in HTTP Switchboard)

See code:

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