If someone is “borrowing” your Wi-Fi service, there’s more to this than just the nerve of someone secretly mooching off of you.

Their use of your service could interfere with bandwidth and mess up your connection. If they’re a bad guy hacker or even a skeevy child porn peddling pedophile and get caught, it can be traced to your connection—and you will have a lot of explaining to do to the authorities when they bang on your door at 4am with a battering ram.

How can you tell if someone’s riding on your signal?

• Log into your router to see what’s connected.
• For less techy people, use the free Wireless Network Watcher to get the list of connected devices.
• Do all the devices on the list belong to you? Any that don’t? Ones that don’t are thieves. You will not know, of course, how often they mooch off you unless you bring up the list regularly.
• Make a record of this device/gadget list (or take a screenshot).

How do you figure out whom the user is?

• Their devices name may coincide with their real name, address or other identifying information.
• But knowing who they are isn’t important. Just encrypt your Wi-Fi network, as this will usually stop the mooching.

Encryption is key.

• Keep in mind a savvy Wi-Fi thief can get past WEP encryption. If this is the case, change your password and make sure you are at least on WPA encryption. Then recheck the device list.

Upgrade and update.

• Unfortunately, many routers have security flaws and hackers can still sneak in through a backdoor in your router.
• Make a backup of your settings, take screenshots if necessary. You will need to reset the router to factory settings, update all software and firmware, and then set things up all over again.
• Bear in mind that changing the encryption password means you will have to update the password on every one of your devices.

What if there’s no intruder but your connection is still slow?

• Evaluate your Internet speed: Do a search for “internet speed test” and see what you are supposed to be getting.
• Check your “throughput”. Throughput is the measurement of data speeds within your home network. You can check your throughput with numerous online tools. This will show if your Wi-Fi speed is slower than the Internet speed.
• Determine how many devices your router will support. Some routers bog down after 5-7 devices. Many homes may have as many as 10-20 devices connected and not realize it. If so, you may have too many devices in the household. Disconnect all but one, then check the speed. If this is the cause, then you need a new router that can handle multiple connections.
• If you only have a few devices connected, however, then you may need a modem upgrade or router upgrade. Consumers already know their devices constantly need upgrading so shouldn’t be surprised that their modem and router need to be swapped out every couple three years.

Robert Siciliano is an identity theft expert to TheBestCompanys.com discussing  identity theft prevention.