I never thought you were passing on personal or CC account details.
Passing on the IP address is enough for site such as google or other sites to track a person's browsing. If you pass my IP address to them and then I go to the BBC, Chain Reaction, etc and they do the same then google can create a profile of my Internet browsing which they can use to sell advertising, etc..... huge profits are made with IP tracking.... That is the only problem that I have with it. Lots of websites pass on this information so it's hard to prevent this practice. However, it's rather disappointing that CC does it too, I'd like to think we are a friendly community looking out for each other - I guess that is not really the case.
It was on the news this week that Twitter has sold every single tweet ever written.....
Did you even read Shaun's post? Nothing is passed to any site, unless you click the Twitter or Facebook buttons.