If you've had an unsecured Wifi setup in your home in the past, you can be fairly certain that at least one of your neighbors is mooching off your Wifi to connect to the Internet. While everyone loves a friendly neighbor, providing an easy resource for others to steal Internet access is morally and legally questionable, but even scarier is the harm those moochers can do to your computer.

In order to check who has been using your network, you'll need to check the MAC address. Every wifi gadget is assigned a unique code that identifies it called the "physical address" or "MAC address." Your wifi system automatically records the MAC addresses of all devices that connect to them. But busting your Internet-stealing neighbors isn't all that MAC addresses are good for, they can actually be a great help in securing your WLAN.

The Problem: You are not sure who or what is accessing and endangering your wifi network, and once you find out that someone or something is mooching off your network, you want to stop them. But how?

The Solution: Checking the MAC address long for your wifi network will give you a quick view of all the devices accessing your network. Anything that isn't yours, you will want to keep out. To do this, you will need to manually key in the MAC addresses of your home equipment. This way, the network will allow connections only from these devices, so your mooching neighbors will be out of luck. Caution: This feature is not as powerful as it may seem. While it will stop your average neighborhood moocher or amateur hacker, professional hackers use advanced software programs to fake MAC addresses.