Palestinians are right and have right to demonstrate. The illegality of the current route has been confirmed by the Israeli Supreme Court in 2007, yet the route was NOT changed on the ground for 3 years. So, demonstrations (I'm sorry but even with slingsshots and stones) are right in such a situatons.
Hundreds gather in protest at CA GOP convention when Trump is set to speak (Haaretz)
from the article: Israel must allow Palestinians to protest in peace