Israeli security forces suppressing non-violent protest in Bil'in have been using a sound weapon lately called "the screamer," which emits piercing noises to incapacitate and disperse crowds as a non-lethal crowd control measure. According to Ha'aretz, on June 20 the use of the device sparked violence at an otherwise peaceful protest:

Some 15 demonstrators and three members of the security forces were lightly injured Friday during a demonstration against the separation fence near the village of Bil'in west of Ramallah. Hundreds of Palestinians, accompanied by Israeli leftists, took part in the demonstration, which began quietly, but turned violent after the IDF operated a device that emits powerful sound waves. Soldiers and police shot rubber-coated steel bullets and tear gas at the crowd, and the Palestinians threw stones. (Ha'aretz, June 20)

See our last post on Bil'in