HotPlug Basic Demonstration

As far as i'm aware, often times they just plug into an open socket on an existing powerstrip that are so often used for PCs, no vampire-ing required. You can then unplug the powerstrip from the wall, it stays powered, inputing electricity through one of the sockets instead of drawing. I guess a more elaborate version of the same idea can be done if the computer plugged directly to an outlet with two sockets too, removing the socket from the wall. The only time I can forsee vampiring the cable being a thing would be if computer is directly plugged into a single socket outlet on the wall? > ▶ this video > link

If anyone's wondering, here's the important bit: ▶ this video I suppose this technique could be modified for most UK pugs too, but I've no idea how you'd manage it for a recessed EU-type socket.

You can't even trust your server if it never goes down. This 5-year marketing video for police demonstrates switching a computer over to another power source without powering down: ▶ this video

They make devices that can safely transfer power from the wall socket to a UPS so that they can take the device with them. Take a look at this one: ▶ this video