Dave, we revoked the citizenship of people who went to fight for ISIS.

The person you refer to,
" a judge said the move was a “suitable and proportional” response after Zayoud ploughed a car into a female Israeli soldier before stabbing three civilians near Kibbutz Gan Shmuel, northeast of Hadera, in October 2015."
Zayoud was convicted of four counts of attempted murder and sentenced to 25 years in jail following the "nationalistically motivated" attack, which came during a spate of stabbings and shootings in Israel.
https://www.independent.co.uk/news/world/middle-east/israel-revokes-citizenship-stripped-arab-israeli-alaa-raed-ahmad-zayoud-haifa-kibbutz-gan-shmuel-a7879771.html