These guys at the Information Awareness Office either don't know their Latin very well, or they are being blantantly evil.
Potentia means power but it has the connotation of unconstitutional private power. Power attained by private means and used for personal ends. What they should say is "Potestas." This is power attained by and for the public good. As in this famous quote by Francis Bacon: Ipsa scientia potestas est. Knowledge itself is power.
In my copy of the "New College Latin and English Dictionary" potentia is defined as: "force, power; political power (esp. unconstitutional power)". Whereas potestas is defined as: "power, abililty, capacity; public authority, rule, magisterial power; possibility, opportunity, permission..."
So by saying "Scientia est potentia" they're just coming out and saying, "Knowledge is unconstitutional political power for a few private individuals." Sounds about right to me. Maybe they do know their Latin after all.
source : article posted at CryptoGon