…is when people perpetuate the myth that second wave feminists burned their bras.
Because it’s just not true. 
And constantly bringing it up, when it’s not true, is just plain stupid.
And I have a low tolerance for such kinds of stupidity.

“It is now more than 30 years since a second wave of feminist activism emerged in the United States and Europe, most publicly marked by a demonstration outside the Miss America contest in Atlantic City in 1968. The ‘freedom trash can’ set up at this event and into which were thrown items of women’s underwear (as well as shoes, false eyelashes and women’s magazines) was meant to symbolise an end of enslavement to an artificial feminine ideal; historically, it has meant that ‘women’s libbers’ would be associated with bra-burning forever. Even though the flames were the creative addition of a reporter, the image has stuck as part of our mass misremembering of the origins of the modern women’s movement”
Overloaded – Imelda Whelehan

“[Jacqui] Ceballos…was also present in 1968 in Atlantic City when feminists protested the Miss America Pageant and the urban myth [my emphasis] of bra-burners was born. ‘It was against the law to burn bras or anything else, but there was a ‘freedom trash can’ out on the boardwalk and we threw in anything we thought was oppressive to women,’ she says.
…One of the reporters covering the protest was Lindsy Van Gelder from the New York Post, who compared the trashing of bras to the burning of draft cards, and ever since people have mentally connected feminists with an imaginary lingerie inferno.”
Female Chauvinist Pigs – Ariel Levy

“The first action of the new women’s liberation movement to receive front-page coverage was a demonstration against the Miss America pageant in 1968…The reason this event got so much ink: a few women tossed some padded brassieres in a rubbish bin. No one actually burned a bra that day – as a journalist erroneously reported.In fact there’s scant evidence of underwear torchings at women’s rights demonstrations in the decade. (The only two such displays that came close were both organised by men, a disc jockey and an architect, who tried to get women to fling their bras into a barrel and the Chicago River as ‘media events’. Only three women cooperated in the river stunt – all models hired by the architect.)”
Backlash – Susan Faludi

So put that in your pipe and smoke it.

I could probably find more, but I like a triadic discourse structure

One more time to reiterate: No feminists ever burned their bras in any form of protest.

Besides, an appeal to history is an argumental flaw if people are basing a large part of their argument or criticism on it. (I do critical thinking, and it’s all about flaws and shit.)
But an appeal to history where the goddamn event never occurred? – Laughable.