El Al, Israel's national airline, has installed the Flight Guard anti- system on some of its airliners. Flight Guard automatically deploys flares to divert an approaching heat-seeking away from the aircraft. It has been used on Israeli military aircraft for a decade.
Last November, unidentified attackers fired two surface-to-air s at an Israeli airliner taking off from Mombasa, Kenya. Fortunately the s failed to hit the plane.
Last week, two El Al flights had to be diverted from their Toronto destination because of reports terrorists were planning a attack on the aircraft.
The Jerusalem Post article can be read here.