2 issues spring to mind:
- What happens when someone puts illegal content on it? Eg child porn. It claims to be censorship-resistant (not censorship-proof), but I imagine any system that cannot expunge data like this won’t be around for long.
- Where are the details on the 1000 years of storage? Have they got financing arranged (and already in trust funds/isolated from the rest of the business) for this storage, the maintenance of the software throughout the next 1000 years etc? Or are they relying on people to contribute resources? If I pay money to store data here (say precious, irreplaceable family photos), then come back in 50 years, what’s the odds that I will still be able to access them?