High tech. Can and is a double edge sword. Gundog go and purchase the best router you can afford. Get one with dual or more wifi antennas. Wired connection is and will always be more reliable.
But nothing is full proof.
About the camera Must likely their computer was hacked and not the camera.
But with out the factual information it is really tough to say. Microsoft explorer or edge has a big hole.
So get control of the computer with administrator rights now one can view the camera and mic.