# NotAllMen was already a Twitter hashtag created by the Twitter user Sassycrass before the 2014 Isla Vista killings .
Hashtag gained additional traction after the event , because of the hatred against women expressed by the shooter , Elliot Rodger .
# NotAllMen was already a Twitter hashtag created by the Twitter user Sassycrass before the 2014 Isla Vista killings , but it gained additional traction after the event , because of the hatred against women expressed by the shooter , Elliot Rodger .