Online Privacy

The title of this article is misleading, because it's really commenting on the whole "how private is your information" issue in terms of Facebook and social networking:

http://www.boston.com/bostonglobe/ideas/articles/2009/09/20/project_gaydar_an_mit_experiment_raises_new_questions_about_online_privacy/?page=full

I guess I've always understood these basic concepts of online privacy:
1) If you post some piece of information about yourself online (social networking, etc.) (data, pictures, etc.) they're out there and you should assume that you no longer have complete control over it.
2) The more information you put out there, the easier it is to correlate and determine other things about you.
3) No matter what a company's privacy policy is, SOMEONE at that company has full access to whatever you've given them, and you can't guarantee that they will not abuse that access.

I'm not trying to scare people, I just want to point out that this is an ongoing tradeoff between convenience and cost vs. privacy and security. Things like Facebook are free, and they are useful services. The tradeoff is that you trust them with information about you. It is certainly in their best interest to try their best to keep your information private, but both them and everyone you allow to see your information (e.g. your friends list) can see everything you put up there, and thus can let anyone else they want to see it see it.

I use Gmail (Google Mail) and many people use other online mail services, and we're trusting these services with the contents of all our emails. We do this because the service is free, convenient, and useful, and so we assume the risk of a third party storing our email data.

The main point is, it's ultimately your choice - if you want to use something like Facebook, which may provide a great benefit to you, you also assume the risks. Be as careful as you can, limit your risk, but remember that nothing is perfect.