Hagai Elad (1969-) is (2014) the director of B’Tselem. He was (2006) the Executive Director of Jerusalem's lgbt community center, the Open House. He was (2010) director of the Association for Civil Rights in Israel
In January 2010, he was arrested, during a demonstration at the Shimon Hatzadik compound in the Sheikh Jarrah neighborhood, by police who claimed that he was violating the conditions of the demonstration by using a megaphone. He spent Shabbat in the city lockup in the Russian Compound, together with 16 other protesters.
See this Wikipedia (Hebrew) article (English translation)