Today I was toying around with netstat to see what incoming connections I had to my Linux box and noticed that for the pages you’re on, your browser makes a connection to each of the ad’s providers linked to on the given page. What’s best (or worst) about this is the connection isn’t broken until you close your browser (at least that I noticed).
I mentioned this to my girlfriend who is a big fan of adblock and she asked (of course) if that happened when adblock was running. So, off I went to install adblock to test and sure enough, it still made the connections to the ad providers' servers. Obviously the ads are hidden, it just still grabs the resources for the ads but obscures their html. That means you’re still being tracked by the ad providers, you just don’t see it.
This isn’t necessarily a bad thing. I mean, before adblock they were still getting your information. Now it’s the same, you’re just not seeing animated gifs and full screen flash ads all over. I’m not knocking adblock at all (in fact, please support them in their worthy cause). I just thought I’d mention this for anyone wondering.