They claim on their website (www.intervigil.com) that they have "strict privacy policies" but is it really ethical to involve a third party without your knowledge that keeps tracking lists. What bothers me is the phrase:
When you visit a website maintained by one of our solutions, either to read pages or download information, we automatically collect and store the following non-identifying information:
· Internet protocol (IP) address
· Type of browser, operating system and desktop settings
· Date and time this site is accessed and duration
· Pages visited
It does identify you personally - they can use heuristic analysis from all their clients, and with a bit of extra information they can link it to personal information like name, id etc. They can built a quite accurate picture of your surfing behaviour as well.
They also place a cookie on your machine.
What bothers me most is the fact that their clients do not give any indication that you will contact a third party.
I will block *.intervigil from now on, because I'm just not in the mood to have all my surfing habits on the servers of a single company.