Power up or nothing

[Dual_Core]

Can someone explain what this light source is? is it just nothing or is it a power up/charger! reason i ask is that i seen some one near one and there was a stream of lightning coming from or going to it from a player online, was he just shooting it with a weapon or was he charging it?
[img=http://img375.imageshack.us/img375/7449/lightsource5ta.th.jpg] (http://img375.imageshack.us/my.php?image=lightsource5ta.jpg)

[DekenFrost]

its "ammunition" for the leech gun .. you learn that in the singleplayer demo

[Chaos Marine]

And just saying, but the code you're looking to use is Address