Switch your router to use WPA or WPA2 encryption. Choose a good, long password which is a mixture of letters and numbers (write it down and keep it safe so you don't forget it!). Use your network management GUI (nm-applet or Network Management or ConnMan, or whatever it is you are using) to change your PC's wireless connection to WPA/WPA2 and enter the password there (you only need to do it once) to enable your PC to connect to the encrypted network. I would not bother cloaking (hiding) the network SSID (name) as that can make connection to it more awkward and does not increase security -- see Re: Cannot connect to my wireless network.
BTW, what hacking of the forums? These forums? If you mean spammers, we get them all the time and the moderators or administrators delete the offending user. This goes on all the time, and a few of the spammers are porn spammers, but most are not.