About as much chance as they'd have of building anything worth $65 million in the first place, which doesn't seem like much. These guys are just the stereotypical "startup idea people" who think "we just need to hire a programmer to implement our vision".
I know Mark Zuckerberg is the villain now, but let's be fair. Just because Facebook's default privacy settings aren't private enough for our tastes doesn't mean Zuckerberg is a psychopath or that everyone who has a grudge against him is the hero.
I have no idea nor any opinion about the merits of their case. I am pointing out the otherwise useful idea of "just shrug it off and build something else" is good advice only in a certain domain, and this is not in that domain. It is dangerous to take advice out of the domain it is appropriate for (a broadly applicable statement), and useful to point out when it is occurring.
Frankly, I don't care how any lawsuit goes. My personal recommendation would be to take the settlement and cash out while Facebook stock is still worth something. I'm not terribly sanguine about the 1-2 year prospect of the stock. (Not because Facebook will be gone by then, but because the current value of the stock includes a promise of growth that I think will be obviously not going to happen by then.)