Hackers On High; Taking advantage of increased use of satellite and microwave communications, the US army is developing a fleet of electronic warfare that will intercept microwave signals, identify the type of data being transmitted, and insert damaging data into the signal as it heads on towards enemy computers. The fleet of 40 new aircraft are to be in service by 2007. In the past, army signals intelligence concentrated on enemy text and voice messages. But the new approach is meant to go after data headed for enemy computers. Using additional computers on the ground, and sharing data with US Air Force electronic warfare forces, the airborne hack attack aircraft will seek out transmissions sending data or commands to computers or computer controlled equipment. Using previously collected data on the enemy systems, and tools for sorting out recent changes, the airborne hackers will try to modify the enemy data. This will either confuse the enemy computers, or make them do something advantageous to American forces. Typical uses would be against computer controlled air defense or artillery systems. It's would also be possible to confuse enemy intelligence or command systems. Messages can also be captured for examination (even if encrypted.) Although less useful against low tech foes, it is the enemy forces with more efficient computer assisted systems that can do the most damage to U.S. troops.