hijack

from The American Heritage® Dictionary of the English Language, 5th Edition.

• transitive verb To seize control of (a vehicle such as an airplane or bus) by use of force, especially as a way of reaching an alternate destination or as an act of terrorism.
• transitive verb To kidnap (a person in a vehicle).
• transitive verb To stop and rob (a vehicle in transit).
• transitive verb To steal (goods) from a vehicle in transit.
• transitive verb To take control of (something) without permission or authorization and use it for one's own purposes.
• transitive verb To steal or appropriate for oneself.
• noun The act or an instance of hijacking.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb To forcibly stop and seize control of some vehicle in order to rob it or to reach a destination (especially an airplane, truck or a boat).
• verb To seize control of some process or resource to achieve a purpose other than its originally intended one.
• verb computing To seize control of a networked computer by means of infecting it with a worm or other malware, thereby turning it into a zombie.
• verb computing To change software settings without a user's knowledge so as to force that user to visit a certain web site (to hijack a browser).
• verb politics To introduce an amendment deleting the contents of a bill and inserting entirely new provisions.
• noun An instance of hijacking; the illegal seizure of a vehicle.
• noun An instance of a seizure and redirection of a process.
• noun politics An amendment which deletes the contents of a bill and inserts entirely new provisions.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb seize control of
• verb take arbitrarily or by force
• noun seizure of a vehicle in transit either to rob it or divert it to an alternate destination