Australia has proposed a revision to its terrifying computer
surveillance law.
I think the various kinds of warrants described in this article are
acceptable in principle. That some do not require a judge's
authorization is very dangerous.
The secrecy requirement — imprisonment for disclosing any information
about a warrant — is a shield for the abuses which every system like this
tends to generate.
The "assistance order" is extremely dangerous unless it has firm and
clear limits about who can the ordered to assist, and what kinds of
assistance can be demanded. Otherwise, what is to stop an agency from
ordering you to put a back door into a program?
Statements about the usual "intended" usage scenarios of that power
are meaningless if nothing stops the government from using it
in other ways.