(a) A person commits the offense of computer tampering when he knowingly and without the authorization of a computer's owner, as defined in Section 15-2 of this Code, or in excess of the authority granted to him:
(1) Accesses or causes to be accessed a computer or
any part thereof, a computer network, or a program or data;
(2) Accesses or causes to be accessed a computer or
any part thereof, a computer network, or a program or data, and obtains data or services;
(3) Accesses or causes to be accessed a computer or
any part thereof, a computer network, or a program or data, and damages or destroys the computer or alters, deletes or removes a computer program or data;
(4) Inserts or attempts to insert a "program" into a
computer or computer program knowing or having reason to believe that such "program" contains information or commands that will or may damage or destroy that computer, or any other computer subsequently accessing or being accessed by that computer, or that will or may alter, delete or remove a computer program or data from that computer, or any other computer program or data in a computer subsequently accessing or being accessed by that computer, or that will or may cause loss to the users of that computer or the users of a computer which accesses or which is accessed by such "program";
(5) Falsifies or forges electronic mail transmission
information or other routing information in any manner in connection with the transmission of unsolicited bulk electronic mail through or into the computer network of an electronic mail service provider or its subscribers;
. . . . .
(a-10) For purposes of subsection (a), accessing a computer network is deemed to be with the authorization of a computer's owner if:
(1) the owner authorizes patrons, customers, or guests to access the computer network and the person accessing the computer network is an authorized patron, customer, or guest and complies with all terms or conditions for use of the computer network that are imposed by the owner; or
(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.