Using the XMLHttpRequest Object and AJAX to Spy On You

My colleague, Bill Lazar, sent me this link: Using the XMLHttpRequest Object and AJAX to Spy On You

He was asking whether I think this is FUD or not.
here is what I answered:

When Ford invented the car, many people said its a tool from the devil, and that people will die by using it. They were right - people die everyday in car crashes - but the benefit cars give us, is obviously worth the risk.

The author is naïve. TheSpywaree developers and "marketers" have such sophisticated ways to collect personal / behavioral information and study our online patterns, that AJAX could prove just another tool for their trade, a bigger shovel in the sandbox, but still WITHIN the sandbox. So - if you want to be completely safe from such attempts - disable cookies altogether (or at least authorize them manually), use annonymizers while doing "sensitive" stuff on the web, or just tell your personal firewall, to block any transmission that includes sensitive information about yourself.

The law of nature is such, that every good thing has its bad. If you don't like to get the "Bad" stuff, you'll have to waive the good stuff as well.

And to finish up with another cliché - those who stand still - go backwards.