Free speech zones? Did George Orwell devise those? Like Bill Clinton his blog used to say, either you got free speech or you don't. This admin obviously doesn't allow it.
"Bill Clinton his blog"? What is this, 1473?
From my vague recollections of law school, I'm pretty sure they have grounds for a Section 1983 action - the arrest itself was a violation of their civil rights conducted by police acting under color of state law...And it seems that they'll have a host of first amendment claims against FEMA and others (as a government employer, they have to abide by the bill of rights).
And that's not even getting to the whole constitutionally shaky premise of the "free-speech zones" - the government does have the right to regulate the "time, place, and manner" of speech (which is why it's constitutional to require a permit for protests, but the criteria for the permit cannot be content-based), but not the content - so if pro-Bush shirts were permitted to be worn, I'm pretty sure the Ranks have an argument.
Unfortunately, it sounds like the Ranks just want to put the whole thing behind them.