It wouldn't work because the mapping isn't one-to-one, it's many-to-one. Google is essentially taking advantage of the fact that it's basically impossible to re

It wouldn't work because the mapping isn't one-to-one, it's many-to-one. Google is essentially taking advantage of the fact that it's basically impossible to reliably reverse a many-to-one function. That is to say, you can never know which "good" instances are actually used in an honest way, and which are used in the "bad" way — and justice systems never go on to assume that all "good" instances of anything must be a substitution for the "bad" term.