I have 2 important questions

[rdbox]

1) how effective is your application? Google and Facebook have a lot of ways to identify users. What does it mean to use your application to make sense? There is a beneficial effect 2) there is a lack of setting up exclusion lists for domains, so as not to use applications in certain sites

[ghost]

Privacy Possum's Readme states:

• Blocks cookies that let trackers uniquely identify you across websites
• Blocks refer headers that reveal your browsing location
• Blocks etag tracking which leverages browser caching to uniquely identify you
• Blocks browser fingerprinting which tracks the inherent uniqueness of your browser

and continues with detailed information on the way it proceeds.

Regarding your second question, if you wish to disable Privacy Possum for a given site, once on that site just click on Privacy Possum's toolbar button then on Enabled which will disable Privacy Possum for that site only, not for other sites. To re-allow just click again (this time on Disabled) to re-enable Privacy Possum for that site.