Conspiracy theorists claim that the Cybersecurity Act of 2009 that has been introduced to the Senate will allow the president to essentially disconnect private networks from the Internet whenever the president wants to.
Granted, the bill is pretty vague in certain areas, however it's quite clear in others. Essentially in case of a cyber attack the Department of Commerce becomes an information clearing house to share threat information with owners of large, private networks, but at the same time the Secretary of Commerce can hold the release of certain information regarding threats to said owners if he or she deems to necessary.
It also authorizes the president to declare a cyber-emergency, which is not defined in the bill, and thus allowing him to shut down any traffic to a given server which is believed to be compromised.
Perhaps most evil of all, it was introduced by John D. Rockefeller! Unfortunately for him it was introduced in April 2009, only has 3 co-sponsors, and is unlikely to see the floor. This is likely due to the fact most bills never see the floor and the bill needs a lot of work.
If more comes to pass with the bill, I will discuss more of it, but right now it just seems like a waste of time.