...the case was ... dismissed ... based on a retroactive grant of immunity by Congress for telecommunications companies that cooperated with the government.
I thought ex post facto laws were expressly forbidden by the Constitution (minus certain exceptions [1] that have arisen in case law over the years). Did it work in this case because it was a civil instead of criminal matter?
Read a little further into your link and you'll find that https://en.m.wikipedia.org/wiki/Calder_v._Bull gives a specific set of criteria for deciding whether a change is ex post facto or a retrospective "mollification". A grant of immunity clearly isn't included.
The law [1] didn't make anything newly illegal or legal for the telecoms, it gave the AG the ability to short-circuit the suits by proving to the judge that they (the telecoms) were just complying with the law, without having the details aired out publicly.
Well, yeah. Having details of your classified foreign intelligence gathering operations exposed because somebody sued the phone company is for amateurs.
I thought ex post facto laws were expressly forbidden by the Constitution (minus certain exceptions [1] that have arisen in case law over the years). Did it work in this case because it was a civil instead of criminal matter?
[1] https://en.m.wikipedia.org/wiki/Ex_post_facto_law#United_Sta...