When the topic of socially-constructed identities -- 'labels', as some would have it -- is discussed in an open forum, particularly when the topic at hand is the proliferating, often ambiguous and confusing set of identities associated with gender and sexuality, a certain peculiar attitude almost inevitably shows itself. This attitude is communicated by certain slogans, such as 'labels are for clothes' or 'we shouldn't put people in boxes'; or by such exasperated questions as 'Why do we have to have all of these labels? Why can't we all just treat each other as people?' And I have to say that it's an attitude I tend to sympathize with. It would be just great if everyone just treated each other as a person first, without making judgments or assumptions based on arbitrary socially constructed categories and we all could be ourselves. So I hope nobody will take it amiss if I say that this is an absolutely infuriating display of privilege that does not endear you to the community you're claiming to support.
A lot of people are more polite about this than I am, but I am who I am. I need to either be blunt or shut up; it's just the way I'm made. By trying to remove 'labels' from the agenda as a topic for discussion, you invalidate my attempt to define myself and understand my place in the social schema. One of the privileges enjoyed by members of a kyriarchal overclass is the ability to pretend that the class division does not exist, that it is unimportant (until the moment when it becomes extremely important and non-negotiable); to ignore the voices of the underclass saying no, that's not how it is for us, our lives don't work that way and assume that their own experience is representative of the way things work for everyone everywhere. This is the act of bisexual erasure in which you're declared to be 'gay, straight, or lying'; of white people who claim that they are 'colourblind' or 'don't see race'; of males who claim they treat the women in their lives as 'just one of the guys'. Members of the underclass simply do not have the luxury of forgetting that they are members of an underclass, or of failing in their attempts to understand how people are going to interact with them based on that fact.
Related attitudes which, though not as viscerally distasteful, are still problematic are those of 'label rejection' or 'label appropriation'. I see these all on a regular basis in debates regarding sexual and gender identities. Somebody insists that 'I may be this but that doesn't make me one of that' ('that' being generally an umbrella term such as Genderqueer or Transgender that the protester disapproves of on one ground or another). Which, you know, is all well and good -- I don't really approve of people getting stuck with labels they don't want to have to live up to either. Except that it really doesn't matter what you, or I, or any individual thinks about it. You're going to get labelled one way or another, anyway; and embracing a label of your own volition is a way of preemptively controlling the conversation, of defining for yourself what you are before others define it for you. Think about it; would you rather be labelled as a Genderqueer, or as a 'freak'? And, yes, others will still label you as they see fit; but having a self-constructed identity available serves as a weapon against that kind of social violence; when you get called a 'freak', it helps to be able to say 'no, I'm not' and have a community of others to back you up, and the larger the community the more powerful the weapon. But by all means, if you don't want to self-identify as Genderqueer I won't press the issue. I just think it's kind of like cutting your nose off to spite your face. (The related, and much more clearly offensive case is of label rejection by the privileged -- "I'm not 'cisgendered', I'm just normal!" And if you can't understand why that's offensive, I'm not sure how the fuck to explain it to you.)
Then there's the case where someone from the overclass tries to get themselves included in the definition of an identity intended specifically to delineate the boundaries of the underclass. I saw this recently during a discussion of identities included in the umbrella term 'transgender', when somebody tried to get 'cisgender' included. Which is kind of funny, since Transgender can be negatively defined as any gender identity which is not cisgendered. People who do this may well have good intentions -- sure, maybe they just really, really want to be included and to help out; but what it amounts to is, as in the 'no labels' attitude discussed above, to attempt to erase a boundary that is very real and meaningful to those on the other side of it. Good allies are needed and welcome in any anti-kyriarchal movement, but they can't allow themselves (or be allowed) to forget that they are not members of the class they are trying to help; that, as much as we all wish that it were not the case, their experience of the social world is simply different in ways that they have never been required to understand.
All of these attitudes are predicated on the seeming basic mistake of thinking that 'socially constructed' is the same thing as 'not real', that it means something will go away if it is ignored. Social facts are just as real as physical facts. (They are physical facts, patterns of neural information embodied in human brains that cause real and physical human behaviour.) You can go ahead and treat a black person just like you would a white person; but that is not going to erase their blackness. It is not, in and of itself, going to change how anyone else treats them; and it cannot ever erase the way they have been treated throughout their life because of the fact that they have been labelled as 'black'. Real social-justice activism means working to put an end to kyriarchies. Trying to pretend they don't exist and acting like you're doing it for the good of the underclass is the exact opposite of helpful.