Now, if only people at US T-Mobile saw your app the way I see it - an alternative way of accessing and browsing the web in cases of emergency - not only would you not get shut down, but you'd be given extra resources to develop this further, public praise on creative use of their services and so on.
Of course, if I was Verizon - whose service you say did not work - I wouldn't wait for T-Mobile to get their hands on you first. I'd contact you immediately and I would make sure Verizon's network worked like a charm.
There's ton of completely free PR to be gained here.
However, unfortunately I don't think emergency use when data services aren't up is a legit use case, since webpages are sent from my server to your phone via MMS and I think MMSes are downloaded via a data connection.