The ISIS cyber army has allegedly hacked the website  of the Syrian Observatory for Human Rights watchdog on July 8, 2015, and threatened its Syrian director, Rami Abdelrahman, for his role in documenting human rights abuses committed by all parties in the ongoing war in Syria.
The news was confirmed  by Reuters. SITE Intel Group also reported the hack on the UK-based site:
— SITE Intel Group (@siteintelgroup) July 8, 2015 
The cyber attack was made by the group, affiliated with ISIS, which calls itself the Cyber Army of the Khilafah, or the self-proclaimed Caliphate, which covers large swaths of territory across Syria and Iraq.
Below is a screenshot of the site, which is now down.