Readers might also be interested to know that anonymity is one of the things constitutionally guaranteed by the First Amendment right to free speech. This concept has been extensively examined in legal jurisprudence for many years. See, for example, https://www.eff.org/issues/anonymity
Personal risk, yes. Malpractice is covered by insurance. Bankers risk their clients' money, not their own (for the most part). As long as they perform their job competently, there is little risk compared to an entrepreneur who has had to quit their job and invest their personal funds into their venture.
"I think that was $342K/year for 99.5th percentile of single filers - you need to take on some risk"
I don't think this is true - all the traditional "low risk" professions have this ability: doctors, dentists, lawyers, investment bankers and fund managers. $300k+ is not unusual for a mid-level person in these industries. Senior people in these industries will hit $1m+ pretty easily without having taken on any significant personal risk. A lawyer 3-4 years out from law school in a large firm is going to be sitting on $200k+ already.
That's a valid point, but there is some validation investors get from Goldman and DST investing at that valuation. I think that DST is investing as principal, so it says something that they think it is worthwhile at that valuation (and DST is not a first time investor so they are familiar with FB's financials).
You can bet that Goldman would have got hold of Facebook's financial statements from it before making that investment. You don't invest a few hundred million dollars before kicking the tires first.
As with all legal matters, you should consult a lawyer to obtain proper legal advice. This comment is, of course, not legal advice and shouldn't be relied on as such, but it may help put you on the right path.
Without reading the contracts, knowing where they were signed, etc., a pretty universal general principle is that if you make a promise to your client, you will be liable if you do not live up to that promise. Some of these promises will be expressly in the contract and some of them may be implied by law.
If you agree to deliver a reliable and accurate system (this is essentially a warranty), then if the system fails to meet that, then you do have a liability exposure there. What constitutes a "reliable and accurate system" is open to interpretation and will affect the extent of your liability, but the point is that the door is open.
Instead of disclaiming the giving of any warranties, often contracts will contain a limitation of liability clause, which caps liability. So, while a software developer may warrant that their system will do what they said it will do, if it doesn't, the most a customer can claim back from them is the capped amount. It is common for this to be limited to the amount the customer paid for the software.