As an 'extension' to earlier questions on this topic (for instance here and here),
- What makes Firefox extensions (appear) more secure than Chrome extensions?
- Do they just appear to be more secure, or are they really?
See also:
- Why do Chrome extensions need access to 'all my data' and 'browsing activity'?
- Worst case scenario, what can a Chrome extension do with "Your data on all websites" and "Your tabs and browsing activity"?
- Are official browser add-ons really safe?
- http://lifehacker.com/5990769/why-do-chrome-extensions-need-to-access-all-my-data
- https://support.google.com/chrome_webstore/answer/186213?hl=en-GB
- https://support.mozilla.org/en-US/kb/tips-assessing-safety-extension
- https://support.mozilla.org/en-US/kb/permission-request-messages-firefox-extensions
