Did no one actually read the damn article?
The law places .gov websites under security control of DHS.
It doesn't give them any other power than that.
From the article first sentence
Under a White House plan, the Homeland Security Department will have far-reaching oversight over all civilian agency computer networks.
And this would be a perfect example of why you need to read more than just the first sentence.
Are you saying it's not talking about the White House plan?