Sometimes a man speaking out against sexism will encounter a silencing tactic in which he is accused of simply trying to score, ie, to interest women in himself by being (or pretending to be) a feminist.
Among Internet Pop Culture, this characterization is often expressed through a term "White Knighting." When used in the context of an argument about Gender, White Knighting is the action of a man criticizing another man for overtly treating a women as solely a sexual object.
The implication of the term is that the critic probably in large shares in the poster's ambitions and viewpoint about women and either A. partakes in a superficially different set of conduct and regards himself superior for it. or B. must be propping up a deficient argument to appeal to, or as part of, uncritical snap judgements of a particular demographic (larger society or women in particular), and therefore the argument does not constitute a meaningful or relevant contribution to the discussion.
The idea's primary use implies a cultural conversation as to what is a meaningful or necessary way of involving a marginalized group and what is superficial or unnecessary. However, its secondary use as a means of blanket discrediting men who take the side of a woman in an argument as being confused or a "sell-out" gives the term when used in reference to gender a decidedly misogynist tinge.