Actually it turns out they have some long-range sonic blaster that hits the bad guys with 150 db of screech.
Here is how you stop pirates. Don't miss the, uh, colorful description of how one man stopped the taking of a luxury cruise ship in 2005:
http://badassoftheweek.com/groves.html
You'll want to read the 2005 story to get perspective because it just happened again, today, but this time they not only applied the sonic weapon but also outran the pirates:
http://www.google.com/hostednews/ap/...4-H2wD94QKL7O0