From "Justice League Unlimited: Divided We Fall (#2.12)"
[after capturing the Justice League
] You are defeated. Any unique information that dwells within you will by digitized. Your physical forms will be deleted. Such is the ultimate fate of this world, but for you, the end comes now.
[Brainiac produces a series of metallic tendrils from his body and begins plugging them into the League members, one by one, and they begin screaming
I am so willing to wait my turn.
[Brainiac plugs into Flash