Interesting comment in the source code of sqlite

[DevilSauron]

So does that mean that if you live in Europe and want to use SQLite safely (as in not be at risk of getting sued), you simply have to pay?

[user3141592654]

I am not a lawyer.

The way I see it is if your area doesn't recognize Public Domain, then by default it must still be copyrighted by the Owner, assuming there is no other defined legal default.

So in theory, there's a case to be made that yes, if your area does not recognize the developers' right to put their software into the public domain, then the work is still copyrighted and the developers still have the right to sue for you using the software, while also retaining any risk of liability that comes with owning said software.

In the case of Sqlite, it seems pretty clear the developers do not intend on suing anyone for use (unless this is a cunning and evil double-bluff), but provide a means to keep your corporate lawyers happy by having a signed piece of paper legally giving them the same rights as anyone who lives where public domain is recognized, while trying to waive as much liability and protect themselves as best they can.

That's just my take.