Why aren't charges being brought? I don't understand.

Alleged actress/solipsistic Madonna: " .....wanna blow up the White House...."

Night t.v. host Stephen Colbert about our President, whether you voted for him or not: "....your mouth is good only for a
c--k holster for Putin..."

Actor Johnny Depp: " how long has it been since an actor shot a President? Might be time for it again...."

Alleged comedian Kathy Griffin posts a picture of herself holding up the bloody freshly amputated head of our President to social media.

Why aren't charges being brought? I don't understand.