The standoff between hostage-taking pirates and a U.S. Navy warship looks and feels like a military showdown, but as a matter of law, it's more like the aftermath of a bank robbery gone bad.

Whether a U.S. citizen is taken hostage at a downtown bank branch or on the high seas, federal authorities can claim the authority to capture suspects and prosecute them in U.S. courts.

That means, if the Somali pirates holding a U.S. cargo ship captain hostage in the Indian Ocean make it off their small lifeboat alive, they may have to answer to the FBI.

U.S. law applies to any crime committed aboard a U.S. ship, or aboard any ship when the victim is a U.S. citizen.

Rarely does that translate into a piracy case. The most common criminal investigation launched in international waters? Assaults committed on cruise ships, then-Assistant FBI Director Chris Swecker told Congress in 2005.

But in this case, the hostage, Capt. Richard Phillips, is from Massachusetts. The ship is owned and operated by Maersk Line Ltd., a U.S. subsidiary of a Danish company. That gives the FBI authority to investigate and, if necessary, arrest.