Haven't seen Borat, or the Ali G Show for that matter, so I have no opinion on the merits of the finished product as an entertainment per se.
But this "back story", which exposes the total dishonesty of the film crew as it undertook production, is pretty seriously disturbing, and portends potential problems for other - and simply honest - filmmakers. At least this one particular scene was shot at the specific location, and with the individual character onscreen, only because of purposeful lies from the initial location scout before shooting, a release obtained by means of blatant fraud and deceit, and the scamming director and camera crew feigning ignorance throughout. Intentional hit-and-run blindsiding is worse than merely unfunny.
Candid Camera always made the point of confessing to the gag at the end of the bit - and (I believe) got releases only after filming and giving its targets a choice. Andy Kaufman never fooled people for the purpose of demeaning them, nor was he ever a coward who had to blindside his targets and then run away to hide behind continuing fabrications of an entire film production crew; his whole point was to be confrontational, and he invited real-time response to him, directly and personally. Jay Leno's often embarrassing man-on-the-street interviews aren't dishonest set-ups by a crew pretending to do something else. The targets of the Daily Show and Stephen Colbert aren't total dupes, they're people with a political agenda (and to the extent anyone is actually operating uninformed, the situation might appropriately be characterized as plain con men getting conned) and I'm not aware that the shows' production crews have ever misrepresented themselves as being anyone other than who they really are.
An alleged comedian who is such a monumental coward he has to bait and switch completely innocent and otherwise unwilling participants into embarrassing situations for the sake of his "comedy" is no more funny than Rush Limbaugh mocking people who suffer Parkinson's disease.
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