False. The Clinton emails were first released under FOIA by the State Department, not by WikiLeaks.
You're mixing it up with the Podesta and DNC email archives, which incidentally contained dirt on Trump as well.
Or you could argue that wikileaks operated much like media outlets do but got sent to prison for it anyway.
Maybe it's because wikileaks didn't direct their partial impartiality in the same direction. That's how they keep media controlled. All US major media outlets support the US war machine. That's true from Fox News to CNN. So wikileaks real crime was not being partially impartial in the right direction while doing journalism. On the mechanics Assange did nothing others haven't.