If they're block by a black sack over their lens, take them off the wall and install them twenty feet higher.
If someone is turning them off, go into your router's settings pages and change the security key. Make it a complicated one and don't tell ahyone what it is.
To find the settings pages, press your Windows key and R together then at the Run box that shows up, type
cmd /k ipconfig /all
and hit the Enter key. A black Command form shows up and the information you need is the Default Gateway and will look like this or similar - 192.168.0.24. Note that down and close the Command form.
Next, open your browser and in the URL bar, type that numeric string and hit Enter. Hopefully the router's administator name and the...