Question: Where did the group who has someone in leadership named Ayman al-Zawahiri attack?
Answer(s):
answer: Taliban insurgency
answer: September 11 attacks

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:organization.organization.leadership ?k .
?k ns:organization.leadership.person ns:m.01vcb_ . 
?c ns:base.disaster2.attacker.attack_s ?y .
?y ns:base.disaster2.attack_process.attack_event ?x .
?y ns:base.disaster2.attack_process.attacker ?c .
}