WTO Gun Laws is a book in Deus Ex: Invisible War. There are multiple copies throughout the game such as in the WTO Terminal in Upper Seattle and in a store in Trier, Germany.
Transcript
Marksmen and collectors should be aware of the WTO enclaves' gun laws. Carrying concealed weapons is permitted, however, some areas will require you to submit to weapons bytecode safety-locking for the duration of your visit. These codes freeze all weapons until the unlock signal is sent upon exit.