So basically a person with an unauthenticated disability can trample all over my public rights without remunerating me or anyone else. That seems pretty discriminatory. So if I have an allergy to dogs and someone brings one to a restaurant where I am eating then I have to leave.

That kinda squelches the tolerance aspects towards disabled people a tad.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)