Source: Max Headroom
Location: in the near future
Threat Assessment: 3. Commercials that cause a small number of people watching to explode.
Limitation: You have to watch.
Personal Note: I believe in concept the blipvert to be possible. Not for head exploding per say, but I believe that the human nervous system could be hacked. What saves us is millions of years of evolution that makes sure the obvious hacks have already been "patched" over. Still, somewhere in our hardwired nervous system is a weakness that someone will find someday.