While it would certainly be visually interesting to witness a full on dino apocalypse, I'd MUCH prefer they let loose a handfull of raptors to terrorise a small town somewhere. I just cannot imagine a scenario where military forces all over the planet would fail to kill off any stray dinos within weeks, should they try to establish themselves in larger areas. It's the same reason I can't buy into the Planet Of The Apes wars starting with such a small group of individuals. Having several secret facilities and organisations spread around the world with access to small populations of dinos could easily be the foundation of at least a new trilogy of JW "outbreak" movies...