Talking about the service you offer, and presenting it open source because the client is, is misleading and sensationalist.

Also, it isn't a Dropbox clone (you wish!).

When I read some of the comments above, I thought "Oh come on, they make the client's source available to prove security, and you're complaining about lack of self-hosting? They're a business!"

But yes, it's not an "open source <something>", it's a "<something> with source available". It's great from a security standpoint, but "open source" implies that all the components are open-source and that you can self-host, and referring to it as "open source <something>" is disingenuous.

That said, this is just the HN post's title. It's not described like that on your site, so that part is good.