The key problem is: they can very easily pull you off the train (to "talk with you"), wait for it to leave and then say "ok, you're free to go." It costs them nothing - it wrecks your trip. That's the whole point. You are in a vulnerable position. That's why they do it on trains and buses.

I'd still like to know if it's legal though

Somehow I never thought of that aspect of it, damn

I hope you're right. Personally I wouldn't depend on telling an ICE agent to read the 4th amendment, given that the admin is showing quite clearly that they don't care whether someone has committed any crime once they're locked up.

I think the point is 2-fold: 1. it gives you a fighting chance of getting out if they do take you in. 2. it's the resistance effort we all have to put in if we want to win a world where the fact that it's illegal might actually stop them.

I suppose begging for mercy is an option. Not one that I'd choose. And between the two choice of "no" and "fuck you, no" I prefer the second one.

The question they're asking is not what should one do. The question they're asking is can they be jailed for it. My point is only that in this moment, the law is not the relevant factor as to whether one might be jailed.