If you’re concerned about the ways your browsing behavior is sold and marketed by Facebook, Google and other search firms, here’s something you can do about it.

A free tool to combat online peeping is available at the Digital Advertising Alliance (DAA) . It checks your computer to see what companies are targeting you with customized ads and allows you to opt out of the targeted ad for each of 177 companies participating with the DAA. Want to know more about yourself and who is really following you? Use the tool to:

• See all the participating companies and learn about their practices;
• Learn which participating companies have currently enabled customized ads for your browser;
• Check whether you’ve already opted out from participating companies;
• Exercise choice with some or all participating companies, using opt-out cookies to store your preferences in your browser; or
• Opt out from all participating companies in one step.

For more information, visit: Digital Advertising Alliance Consumer Choice Page. In the meantime, be careful about which ads and Facebook posts you click on when using the Internet and social media platforms. Big Brother is definitely watching.