Why hijack a plane when you can seize a supertanker?

SINGAPORE (Reuters) - When pirates armed with little more than AK-47s and rope ladders seized a supertanker last week, they showed how simple it is to storm a ship -- a vulnerability that al Qaeda could exploit to attack the global economy.

Security analysts say the ease with which Somali pirates have captured a huge range of vessels illustrates how much more at risk global shipping is to terrorist attack than the airline industry, which massively improved security after September 2001.