These two systems are now required by law (international agreements) for all sea going vessels greater than 300-tons. The technology has worked, and the U.S. Navy has found them particularly useful in counter-terror operations. Coast Guards the world over have also found the systems a big help. But apparently pirates in some areas have gained access to the systems (via bribes or theft) and an increasing number of pirate attacks appear to have been helped by technology meant just to safeguard ships at sea.
Maritime security technologies are being turned against their users as pirates apparently get access to tools shipping companies use to safeguard their ships. AIS (Automated Identification System) and INMARSAT (International Maritime Satellite) were originally developed to make it easier to track ships at sea. AIS is essentially an automatic radio beacon (transponder) that, when it receives a signal from a nearby AIS equipped ship, responds with the ship's identity, course, and speed. This is meant to enable AIS ships to avoid collisions with each other. INMARSAT is a more elaborate system and longer range system. It enables shipping companies keep track of their vessels, no matter where they are on the planet. INMARSAT uses a system of satellites, which transmit AIS-like signals to anywhere on the oceans. It only costs a few cents to send an INMARSAT signal to one of your ships, and a few cents more to receive a reply.