The U.S. has uncovered evidence that cyberspies, most likely from China and Russia, have penetrated the U.S. power grid and left behind software that could be activated to disrupt American infrastructure, FOX News confirmed Wednesday.

The "intrusions," first reported by The Wall Street Journal, have occurred over a period of time, one U.S. official said -- not all at once.

The breaches are "something we're concerned about," a U.S. official told FOX News.

The concern is that any software could be activated at a later date to disrupt critical systems.

The intrusions were not just limited to the electrical power grid, but affected systems like water and sewage.

http://cnintruth.com/2009/04/08/electricity-grid-in-us-penetrated-by-spies.aspx