While the Shin Bet may use aggressive means to obtain information it is far less than other countries the US of A has diplomatic relations with. So called torture or harsh interrogation exists in all countries including democracies. We in the US of A have used torture to obtain confessions and information. The Arabs.. they behead you, castrate you and do all sorts of wonderful things... just because they arrest Jews as spies. When it comes to security of Israel which is one war away from annihilation, the use of extreme force is justified. Better yet, do not live in a country you will spy against.
German authorities accused of playing down refugee shelter sex crime reports (Reuters)
from the article: Israeli Arab activist confesses to spying for Hezbollah