There was a time when neither the head of Shin Bet nor of Mossad were publicly identified; today the chiefs are well known but the second-echelon officers are referred to only by initials. Thus Ha'aretz, due to military censorship, has to be circumspect:
I don't generally care for exposing security officials' identity since it can subject them to danger, but this has been on YouTube since July (an earlier story before the leaker was identified is here) and besides, if the hardline settlers are out to get him, he must be doing something right. As the Israeli press (who tend to find continuing military censorship of stuff everyone already knows annoying in the age of the Internet) no doubt expected their readers to do, it took me only minutes to learn that "A." is Avigdor Arieli, that the "tiny settlement in the West Bank" is Kfar Edumim, and to find the YouTube video, shown below.
The Shin Bet official, known only as A., is the head of the service's Makhlaka Hayehudit ("The Jewish Division"), which is tasked with monitoring the activities of the extreme right wing in the West Bank.
A. resides in a tiny settlement in the West Bank. Military censorship laws do not permit media outlets to publish A.'s full name and place of residence, though this information is common knowledge among wide swaths of the settler population in the territories.
The video allegedly uploaded by the 17-year-old Hebron resident, and which has been available online in recent months, clearly exposed the face of the top Shin Bet commander as he was patrolling the West Bank city, and included a caption indicating his full name.
Though the video claims it was posted by a whistleblower outside of Israel, it appears the authorities have concluded otherwise.