When you break a string attached to a pair of tripwire hooks, it doesn't set its state to disarmed, and breaks the string entirely. This feature is falsely claimed to be a bug in this bug report: MC-129055 This breaks an intended feature by notch, where disarming string makes the tripwire not send any redstone signal.

Steps to reproduce:

1. Place string in between two tripwire hooks facing each other, they should connect
2. Using shears, left click on the string you just placed down
3. The string will break, instead of going into the disarmed state