The decision of Public Security Minister Gilad Erdan to introduce cellphone blocking technology to high-security prisons is logical. For years, Israel's Prison Service has been fighting the smuggling of cell phones that enable Hamas and Islamic Jihad prisoners to transmit instructions for terror attacks from within the prison cells.

The Israel Prison Service occasionally searches prisoners' cells for phones, usually after receiving intelligence about them. One large operation took place in August 2016, when the Prison Service raided the sections where Hamas prisoners were jailed in the Nafha and Eshel prisons, transferred the prisoners to nearby facilities and conducted a thorough search for the hidden devices. The prison administration announced that in addition to finding cellular devices and SIM cards, they also uncovered instructions and directions for conducting terror attacks outside the prison. 

Two years ago, Knesset member Basel Ghattas of the Arab Israeli Balad Party was convicted of smuggling cell phones to a security prisoner in Ketziot Prison and sentenced to two years. As a legislator, Ghattas was allowed to meet with Palestinian prisoners, but he was caught giving cell phones to a Hamas prisoner. In court, Ghattas argued that he acted from humanitarian considerations without intent to harm national security.

A phone is of great value in a prison. It allows incarcerated leaders to retain their status in the hierarchy of their movements, transmit organizational messages and even direct terror attacks. A phone also allows the prisoners to remain in close connection with family members and friends. It is difficult to judge the extent of the issue and estimate the number of phones among the thousands of security inmates imprisoned in Israel. However, according to one security source who spoke to Al-Monitor under condition of anonymity, there are probably several dozen such devices scattered among the various facilities.