She kept blathering about how the FBI can't be allowed to "spy" on citizens, so Russert then asked her if Congress can prohibit the FBI from such things as going into public places, including the internet, to gather information -- and her response was the blatantly egocentric and unconstitutional statement you quoted.
Actually putting restictions on the FBI would be a valid exercise of Congressional power. The FBI is not a constitutionally mandated entity, and the Congress is free to abolish the FBI, root and branch, or to require its agents wear a purple clown nose when on duty, or to restrict its information gathering powers. Whether this is wise or not is a different debate. (I'm assuming, arguendo, that establishing the FBI was a consitutional action.)
Until the New Deal, this country got along quite well with Congress as the predominant branch of government. Whether a return to Congressional dominance would be a "good thing" or a "bad thing" is again a different debate.
Jack