Wurdearring: 3 fan de 5 stjerren

I would have given more stars but I am concerned about the permissions required for installation which says the extension "requires your permission to have full,unrestricted access to Thunderbird and your computer". Why the computer ?

Dizze beoardieling giet oer in eardere ferzje fan de add-on (2.5). 

This is the standard permissions popup for all add-ons.