The BBC has a report on modern day pirates and the various activities they undertake to earn money.

From BBC News:

According to the International Maritime Bureau, which runs the piracy-reporting centre in Kuala Lumpur, pirates attack different kinds of vessels for a variety of reasons.

In Nigeria, pirates tend to attack vessels involved in the oil business, while in South East Asia, mainly small tankers, tugs and barges are seized.

Cargo is often stolen from barges and crew members are kidnapped and held for ransom.

One of the global hotspots for piracy is off the coast of Somalia. There, pirates are active in various black market activities such as illegal fishing and kidnapping and ransom.

Somalia has no navy, so many militia groups have taken it on themselves to deal with the problem of illegal fishing.

“Illegal fishing costs Somalia $6m annually and around 800 vessels from around the world are involved,” says Mr Mwangura.

Pirate fisherman provide cheap fish for home markets, Somali pirates support their towns and villages. That raises a key question: is helping your own people good or bad?

Kidnapping and Ransom is able to generate huge sums of money for the pirate groups.

“All the attacks off the coast of Somalia are aimed at hijacking for ransom,” says Capt Pottengal Mukundan of the International Maritime Bureau.

“The idea is to seize the ships hundreds of miles off the coast, force the ship well inside Somali waters and then the hijackers keep the ship until the owners pay an agreed ransom for the return of the ship and crew.”

The amount of money that is demanded by pirates is often substantial.

“In all cases where the vessels have been released in Somalia, they have been paid,” says Capt Mukundan.

When a Danish cargo ship, the Danica White, was seized by Somali pirates in June 2007, the ransom paid to secure its release was reportedly as high as $1.5m.

Illegal fishing is a $4.5 billion industry worldwide.

Kidnapping and Ransom generates $500 million worldwide.