Question: Are Naser Mestarihi and Justin Sane both singer-songwriters?
Sentence (from "Justin Sane"): Justin Cathal Geever, known professionally as Justin Sane, is the lead guitarist and singer/songwriter of the United States-based musical group Anti-Flag, a punk rock band formed in 1988 in Pittsburgh, Pennsylvania known for its outspoken left-wing views.
Relevant evidence: Yes