You're implying I or others wouldn't care about rape, but would care about leaking personal info? That's a bit offensive actually and really needs to be backed up with a lot more than just an assumption.
To address your analogy. If a security flaw in the form leaks personal info and privacy of tens of millions of people is compromised as a direct result (like has happened), that's a bit different from an indirect result in a screening process that affects a single person. Consider that statement beyond the fact that this seems like an incident, as I'm not trying to make a numerical comparison between the two examples here. What I mean is that one is a direct consequence, while the other is not. That is, I wonder if there is any screening process that could have prevented this, if there was any one thing they forgot to do that directly caused this event.
Using your analogy, if the security form leaked only a single piece of information and the leak was due to say a third party (like the driver in this case, say it'd be a problem in the Chrome browser) that Uber should have noticed in development, it wouldn't be a big deal and beyond the technicality of the particular security flaw, it's not relevant. I wouldn't flag it, but I'd easily see why others would.
Anyway I don't want to push this analogy much further as frankly I don't feel comfortable with it, I certainly don't want to belittle this rape and compare it to something non-trivial like a security form. Apologies in advance if anyone felt that way about this post.
To get to the actual point: what is uber's responsibility? I think that's the key question here. It's a bit of a tricky one. Uber kind of sits between two positions. The first is that it's 'just the facilitator', and can't be fully responsible for 3rd party drivers. Of course it'll claim to aim to feel responsible, but in the end uber drivers aren't like real employees. Uber kind of feels like more of a freelancer on odesk type of place, at least to me, where Odesk would have limited responsibility. On the other hand, they also try to position themselves as a quality brand, as distinctly Uber, as a company with its own drivers, not random freelancers on its platform. It's clear they have responsibility, but how much?
Anyway, perhaps that's not the correct question. A more specific question would be: what kind of screening process could they have had that prevented this?
You said this: > But a rape happens because of security flaws in the driver signup process
But I wonder what exactly that flaw was. Sure there's a chance he did this before and was registered somewhere and a background check would let that fact surface, but I think it's unlikely. Most rapists aren't the cliche-criminal, it's usually an uncle, a boss, a friend. It's likely none of these people, nor likely the driver, would carry stereotypical characteristics of a person you'd want to reject in the hiring process. Meanwhile, Uber does have his identity on file and records of the trip, so it's likely he'll be caught just as quickly as an employee of any other company. As such I still wonder if this isn't just an incident unrelated to company policy like the case of the rape of a Polish woman earlier this year in India in a regular taxi.
Anyway I have no clue about what kind of screening they do and what kind of screening is typical for drivers at a taxi company. If anyone is privy to this info let me know! In any case I think it's a clear signal Uber should improve its screening process so that we'll never hear from a case where someone was raped in a taxi by someone with a record of having done so before, as that means it may have been preventable with better screening.