I'm no "right-wing Zionist", but here's my definition of legitimate criticism: criticize a particular policy, a particular person's opinions (not the person himself) or a particular event--but do it even-handedly. As an example, criticising Israel for Operation Cast Lead while ignoring the 8,000 plus rockets fired into Israel prior to the operation isn't legitimate criticism. Criticizing some of the events that took place during Cast Lead are legitimate--as long as you present ALL the facts and not opinions, innuendo and unconfirmed rumors.
Afghanistan examining claim Taliban leader Mullah Omar died (AP)
from the article: For Israel, 'delegitimization' is becoming an excuse