However that seems to me to be all the distinction is. Costolo is a public figure. A multi millionaire, almost certainly richer than Trump, and there are violent activists who support his kind of rhetoric too.

It seems pretty clear that Twitter not censoring his tweets the way they have with Trump is based on a political distinction.

You could even see his statement as declaring Twitter itself to be an activist organization that sees revolution as inevitable and is working towards that aim.

That would undermine the idea that it’s somehow at a different level of seriousness to Trump’s tweets.

Costolo is talking about murdering business people whose ethics he disagrees with.

He could be instead be talking about voting out Trump and reinvigorating democratic institutions, but he isn’t.

I made a case. I didn't say I subscribe to it. I don't.

That's what I tried (and apparently failed) to convey by concluding "it's a violation, all the same"