This is an article that I found that may make you fully aware of your online activities, and why you are getting junk mail, and junk phone calls and such. This is another way for Big Brother watching you when you are not online and online. It's best to limit what you do or say online these days. Here is why.

Often called aggregators, these sites build profiles about you based on information from online and offline sources such as phone directories,
social networks, photo albums, marketing surveys, mailing lists,
government censuses, real estate listings, and business websites. These
sites often include demographic data, property values and estimated
interests gleaned from the information they've collected. These profiles
can be used for any number of reasons, including marketing –
advertisers can often buy detailed lists from these sites and start
mailing or calling you.

Here is more of the story.

http://daol.aol.com/articles/you-online?icid=main|main|dl6|link1|ht...