omg hax

Someone just removed the password from my WiFi network and also tried to DDoS some site using my IP, what should I do? I already disconnected my WiFi router so they can't persist but I wanna have a wireless network again...

And before you ask, I hid my SSID so that supposedly only people who are already on the network can view it, and I used WPA2 encryption... Yet that still didn't stop them.

Ah i answered before i read the whole thing...
Assuming you have a linksys router... When you pick a WPA key pick one besides the first option (not sure if other routers have that) also try setting up MAC filtering. They probably got in by sniping packets. About a week straight does it. For added security change the WPA key each week.