I am wondering if a PC that has CAM software could safely be connected to the net.

[JAZZCNC]

Based on the fact I know steve is running Mach3 then If your running an external motion control card you'll be much safer than running parallel port driven machine.
PP based can't afford for any interupts from the system and Internet can be problem, esp if machine is low spec or tuned on the high side so PP is working hard.

In all cases it's a little like playing russian roulet you never know when you'll get the bullet.!! . . . Often machien will give blip and the mistakenly gets blamed on something else when it's the Tinternet that did it in the background.!!

My suggestion is to turn off the Wifi while cutting and then turn back on if you need to make changes to Cam.