This shouldn't be a surprise..
It's the "computers don't count" argument.
They don't count as telephones, therefore spying on your email, chat and browsing history doesn't require a warrant.
They don't count as private property (cars, houses, letters) therefore a warrant is not required.
They are a world unto themselves and because they're new things, annoyances like The Constitution or indeed the law itself doesn't count.
The reason none of this should be a surprise is this is the same tactic prosecutors use every time a new technology becomes mainstream.
When telephones became mainstream, the government said they could listen in because the Constitution only protected people from being searched, not things.
It took a Supreme Court decision to change this. The same ruling could in theory be applied to computers, computer data and computer communications, but the government will say it doesn't count because computers weren't around when that ruling was passed, and deliberately ignore the intent.
The fact is The Constitution and its protections were supposed to be updated to stay relevant. A system called "Amendments to the Constitution" was invented for this very purpose. That's because the people that devised these laws had the foresight to understand that things change, new things are invented, new circumstances occur and new beliefs as to what is acceptable become mainstream. It's quite progressive thinking really for a bunch of people who've been dead for centuries.
Therefore regardless of whether we would like to see pedophiles self-incriminated to make our lives easier, the fact remains other laws state he is innocent until PROVEN guilty. The media doesn't count, neither does the government's promise that 'he is guilty, honest'. Whether showing the cops something is self-incrimination or not apparently requires a new Supreme Court ruling, preferably one that includes computers in general and whether conversations via modern communications that people want to be private, count as private.
I wonder what corporations will think of that when people start taking copies of data stored on networks home with them, including things that used to be intellectual or private property.