The Constitution? What's that? People who use computers don't need no stinkin' Constitution!
Seriously, using a computer is all it would take. With this proposal, the government could go to the FISA Court -- the powers requested would probably simply be added to its charges, since it already exists -- and say, "We think we ought to be able to tap this person's communications and search his things without telling him because we think he's a hacker." They wouldn't really have to offer proof -- the FISA court has rejected exactly one request in all the years it's existed -- and you'd never have a chance to defend yourself against the charges because, of course, you wouldn't know about them until it was far too late.
12/19/2001: vive la france
12/19/2001: princess, redux
12/19/2001: yemen and rumsfeld
12/18/2001: you're NOT in the army now
12/18/2001: interesting donation
12/18/2001: shame on winn dixie, indeed
12/18/2001: saudi princess
12/17/2001: new resolve
12/17/2001: a victim of the attack ... yeah, right
12/17/2001: polluters ho!