In the state of Maryland, it's against the law for anyone to tamper with another's bicycle:
ANNOTATED CODE OF MARYLAND – TRANSPORTATION
Bicycle Related Definitions and Laws
21-1206 Carrying articles; tampering with bicycle, motor scooter or EPAMDs.
(c) Tampering with bicycle, motor scooter, or EPAMD. – A person may not remove, ride on, or tamper with any part of a bicycle, an EPAMD, or a motor scooter without permission of its owner.