No, thats not true. I've heard of people somehow wiring that shit to work with like a battery of some sort. I dont know though, but the power supply would be overkill to power just a computer fan.
all you need is a 12v adapter that goes from the fans molex connecter to a 12v power connecter that goes straight into your wall outlet. very easy and it can look sick if you get a light up L.E.D fan :hump:
you could buy a power supply for a comp and plug that in to an outlet and then plug the fan in to one of the connectors on the power supply. Just dont connect it to the comp.
i cut allt he wires and bought 18 guage wire and wired all my computer fans together and plugged it into a socket, works like a charm in my grow box, been using them for a while no fire yet.
you should get an ac to dc wall adapter, those big block looking power cords. It must be 12V! With this there will be 2 wires, 1 neg, 1 pos. find and connect neg to neg and pos to pos on the fan and should work fine. Beauty of this it can have multiple fans if it stays a good voltage.