Startups that are based on user-contributed content are based on fraud in the sense that they imply to their users that the contributed data will always be available. But it's a lie, the user's data is only being used to explore a potential market. If the market idea proves successful the company will be sold and shutdown. If the idea is unsuccessful it will also be shutdown.
Startups should be required to tell users upfront with a big warning that the business is not profitable, how many months of runway the startup has, and that all data could be lost at any point.
No. Private companies should not have to disclose their runway or profitability as this gives competitors insight into the market. Imagine if Pandora plastered a big notice on their signup that says they're not profitable so beware of creating new channels because who knows what will happen. Same is true for Facebook in the early days. It's just unnecessary and business should not be conducted by trying to optimize users away from your product. Of course, I like when companies are fair about how they go about their shut down (e.g. Posterous with ample time to backup your content and go elsewhere).
Startup projects at bigger companies could be just as risky as a startup company. Where do you draw the line on requiring such a warning? It doesn't sound realistic to me.
While I don't think forcing private companies to reveal this information is right, a legal requirement to support data exports (including for up to 30 days after the announcement of a closure) seems in society's interest.
Startups should be required to tell users upfront with a big warning that the business is not profitable, how many months of runway the startup has, and that all data could be lost at any point.