Overview: In 'Live Free or Die Hard,' the fourth chapter in the high-octane action franchise, a mastermind cyber-criminal holds America hostage by wreaking havoc via the Internet. It's a great thriller, but could this imagined scenario ever happen in real life? See how an all-out cyber-attack on the U.S. is a very real possibility.

DVD Verdict: For those not in the complete know, as the nation prepares to celebrate Independence Day, veteran cop John McClane (Bruce Willis) carries out another routine assignment: bringing in a computer hacker (Justin Long) for questioning.

Meanwhile, a tech-savvy villain named Thomas Gabriel (Timothy Olyphant) launches an attack on America's computer infrastructure. As chaos descends around him, McClane must use old-fashioned methods to fight the high-tech threat.

Yes, that's the plot for 'Live Free Or Die Hard,' starring Bruce Willis, but here in 'The Real Story - Live Free Or Die Hard (out now from Smithsonian Channel / PBS), we see how an all-out cyber-attack on the U.S. is a very real possibility.

Along with meeting the government officials and former hackers tasked with ensuring our digital space is safe, the documentary does make us aware that cyber attacks are unavoidable; but that we’re not going to stop using computerized systems.

Instead, we should be preparing for the inevitable, including a major cyber attack on power grids and other essential systems. This requires the ability to anticipate not only an unprecedented event but also the ripple effects that it could cause.

Based on conversations had throughout this documentary, preparedness for a major cyber attack like this is low, regardless of whether you’re talking about the regional or city level, or the private sector.

As Lawrence Susskind, a professor in MIT’s urban systems department, described it to me, “Millions…could be left with no electricity, no water, no public transportation, and no waste disposal for weeks (or even months)…. No one can protect critical urban infrastructure on their own. Nobody, though, is showing any leadership.”

Of course, there's much, much more to this 'The Real Story - Live Free Or Die Hard' documentary, but I'll leave it there for now - so you yourselves can learn more about our possible future via this eye-opening Smithsonian Channel / PBS documentary. This is a Widescreen Presentation (1.78:1) enhanced for 16x9 TVs.