Facebook, Google, Apple and Amazon haven't joined the new anti-travel ban brief

Because it's no longer beneficial for them to do so.

The main news cycle window is over, the shock effect has passed, news outlets don't run stories 24/7 about some poor millennial with an unfortunate skin complexion stuck at an airport.

Nothing to gain from a PR standpoint and everything to lose from a political one with the current administration.

Neither of these companies really makes decisions based on morality they do it based on calculated risks and benefits.

They need to administration to ease on h1b restrictions and don't make it harder for them to store money offshore and use it as a credit line without officially repatriating it.

So standing up for one kind of brown people takes a back seat so they can import another kind.

Note: if you have problem with the language of this comment google ad absurdum.

Could it not just be that it's redundant for them to sign on the second brief? Opposing the first ban is obviously opposing the second. I don't think it needs to be some conspiracy about corporate politics and PR.

Strange. Is political pressure out of the question?