How to kick someone off my wifi?

Well, I have been trying to download some software for my mac but all of a sudden my internet is too slow to download it. I downloaded a application that hows whats connected to my wifi. It turns out that my next door neighbor's son has his iPod, xbox, laptop, and iphone connected to my internet. I have a MAC so please tell me how to kick him off or ban him. Any thing works i just want him off!

Added (1). I ALREADY HAVE A PASSWORD!

Set a password for it:)

Put a password on your wifi.

Start by changing the password on the router (or adding one if there ins't one already). Also, what kind of router do you have? Some allow you to block certain MAC addresses or only allow on those you allow.

Login to your router and set WPA security on your wifi with a password that you know. You will need to use it on your Mac to connect to the router.

You should be requiring a password for access. Check with your internet provider if you're not sure how to set it.

You're lucky it's a kid. People have had the cops bust into their house in the middle of the night for illegal stuff other people download on their WiFi's. Plus, an open connection can be used for identity theft by people who know how to exploit it.

Steal all his stuff… Haha jk. You can set a password on you wireless connection. It's different for different routers. Just google how to do it. It only takes about 5 minutes

Use MAC filtering on the security page of the router then only the listed mac addresses can connect, I presume you have a WPA/PSK password