Ok I have done NUMEROUS tests on my router and modem and have come to the conclusion that someone is stealing my bandwidth.
Can someone either:
1 - tell me how to find out if someone is taking it? A test of sorts...
or
2 - tell me how to lock out anyone outside my house. I have 2 wireless computers and 3 hardwired computers in my house and want to keep them online.
Any

is appreciated.