I don't really understand why so many politicians are writing laws that make invasions of privacy possible "without a warrant". Why don't they just require a warrant? Then there are checks and balances, and everyone's happy.
Warrants are issued by judges. There are few things that a politician hates more than having to answer to a judge.
All of the Internet surveillance and censorship policies proposed and implemented around the world attempt to bypass judges. USA (Patriot Act), Australia (mandatory filtering), and now Canada. The usual excuse, of course, is that things on the the Internet move too quickly to wait for due process to take its course.
