In Illinois (and probably other states) it is illegal to violate the T&Cs of a web site:

  720 ILCS 5/17-51 Computer tampering.
  (a) A person commits computer tampering when he or she knowingly and without the authorization of a computer's owner or in excess of the authority granted to him or her:
    (1) Accesses or causes to be accessed a computer or any part thereof, a computer network, or a program or data;
  (a-10) For purposes of subsection (a), accessing a computer network is deemed to be with the authorization of a computer's owner if:
    (2) the owner authorizes the public to access the computer network and the person accessing the computer network complies with all terms or conditions for use of the computer network that are imposed by the owner;