There you are surfing the Web, minding your own business (or others’, thanks to those gossip blogs), and all the while, strangers are secretly giving you cookies. No, not the dunk-in-a-glass-of-milk kind. These cookies are small files that websites place on your hard drive. Read on to find out how they crumble.

What do cookies do? They remind websites who you are. When you shop online and place that wrap dress in the shopping cart, the store tags your computer with a data file so it recognizes that the dress belongs in your cart and not someone else’s. Cookies also help websites remember your user names and passwords.

But with the cool comes the creepy: Websites don’t have to ask your permission to store cookies on your computer. Also, some cookies can be used by sites and their advertisers to track your browsing habits to cater pop-up and banner ads to your interests. And that may leave you feeling as if the salesclerk from the last shop you visited is now following you on your errands around town.

How do you get rid of them? First you have to find them. The easiest way: Search “cookies” in your browser’s help menu and follow the instructions. You can then usually toss the cookies by selecting an option like “Remove All,” depending on if you have a Mac or a PC. Without them, you’ll have to reenter some information (like user names and passwords), but at least you won’t feel as if your privacy is constantly being invaded by cookie monsters.