This common French phrase meaning "to shock the middle class"
is now naturalized into English. It describes breaches of conventional
decorum which discomfort members of the middle class. Such breaches can be
unconscious or calculated, depending upon the person(s) performing them. In
the latter case the shock is usually applied under the simplifying assumption
that the middle class as a whole is both unimaginitively convention-bound and
self-satisfied. Épater le bourgeois attacks often
hope to jar the ostensibly cozy, apathetic, monolithic middle class to some
sort of introspection, though they are also often meant simply to hurt.
A few examples will illustrate the principle. First, unconscious breaches.
Upper class persons are socially secure regardless of what they do (thanks
to things that can't be taken away from them such as an old family, a title,
or having just the right experiences in growing up), and can afford to sacrifice
conventional dignity. Paul Fussell once wrote (in Class) of the
often badly-frayed clothing unselfconsciously worn by male members of the upper
class at all occasions. In such a suit, a middle class person would tend to
be worried about looking shabby (and being socially demoted in people's minds),
and those particularly sensitive to what they think others
think of them wear the newest, cleanest, best tailored clothing they can afford
(I see a lot of university administrators guilty of this). When a middle-class
person encounters someone who is shabbily dressed, they tend to interpret that
person's actions in the light of their own values, and see upper class dressing
down as a deliberate snub, whereas the upper class person really just doesn't
think that much about such conventions.
The classic examples of épater le bourgeois attacks are
those from the side, as it were, that is, from angry or jealous people who either
feel like unjustly excluded outsiders or wish that they were outsiders and would
like to distance themselves from middle class values. The emotions
which fuel these attacks are often thoroughly justified,
and such breaches are not infrequently offered with a "fuck you!"
attitude. Social commentary and attempts at reform often accompany attacks
arising from the artistic community. A Google search will rapidly turn up
filmmaker John Waters as an example. His early camp films, especially Pink
Flamingos, were a natural combination of épater le bourgeois
and social commentary. Although later developments now make it seem trivial,
that period in the 1970s when "liberated" women first began publicly
eschewing bras and allowing it to be known that their breasts actually bear
nipples generated just the calculated shock it intended. Probably everyone is
familiar with Andres Serrano's Piss Christ, or Robert Mapplethorpe's
self portrait with whip by now, the latter being a particularly fine example
because it was printed up in glossy middle-class museum catalogues featuring
a retrospective of his work. Where I live, The Vagina Monologues
still excite shocked comment.
Sometimes the calculation is not malicious, as when Britney Spears' handlers
systematically downgraded her clean image to permit her to transition
to the adult lusts more suited to her advancing age. The antics of Michael
Jackson seem merely confused.
Humble thanks to my friends who corrected my illiterate French misspelling in the first version of the node title. I'll try to find a bug I can eat (preferably chocolate covered). | 
