You can reduce the access to the personal profile that you present (unknowingly,) by blocking and/or reducing access to you as a demographic. There are lots of ways to do this, but I'm currently pleased with a Firefox extension called NoScript. http://noscript.net/
Not only does it speed up page loads by blocking Flash apps, but it allows you to block java script loads and redirects. I was surprised to see how many of the data collection instruments are google products.
My thanks to Bob and the bloggingheads megacorporation for being among the minority of websites that aren't
collecting data surreptitiously.