Re: We are the government
Comey, as a lawyer, should know that whether a precedent is set or not is not under the control of any of the parties to a case, and there is no way any of them can tailor their submissions to change this. Also I am troubled by the fact he claims he is only interested in unlocking this single iPhone 5c, because if that is really true he is not doing his job properly [1]. And if it's not really true, he's not really telling the truth.
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[1] Don't get me wrong, I'd like the FBI etc. to have boundaries on what they can do, but in a sensible society these boundaries should be set by legislation and the courts, not by some voluntary backing off by the organisations when they think they have sufficient powers.