My sister objected me in going to an Islamic circle

The talk was about the war in Isreal, but a jew was killed by a muslim nearby where the meeting was going to take place but the meeting cancelled cos the student union at the university said we were a threat to Isreal and the rest.There is graffitti every where in London saying kill all the jews. My sister told me not to get involved and said to me to stay out of trouble and not attend the meetings. What shall i do?