Nothing in any of the provisions of this Act by virtue of which conduct of any description is or may be authorised by any warrant, authorisation or notice, or by virtue of which information may be obtained in any manner, shall be construed—
(a)as making it unlawful to engage in any conduct of that description which is not otherwise unlawful under this Act and would not be unlawful apart from this Act;
(b)as otherwise requiring—
(i)the issue, grant or giving of such a warrant, authorisation or notice, or
(ii)the taking of any step for or towards obtaining the authority of such a warrant, authorisation or notice,
before any such conduct of that description is engaged in; or
(c)as prejudicing any power to obtain information by any means not involving conduct that may be authorised under this Act.