Unless you've been living under a rock, you know that the internet is full of people search websites that sell your personal information. There are a plethora of these sites like MyLife.com, Intelius, iSearch, White Pages, etc. And for a price, anyone can discover your age, address, cell phone number, shopping habits, etc.
Here's a page with information on how you can Opt Out of many of these sites. I haven't tried this yet - but you can bet I will over the next few days. So as always... your mileage may vary.
HOW TO REMOVE YOURSELF FROM PEOPLE SEARCH WEBSITES