[cocktailpeanuts]

then it would simply mean it is not open. When someone creates something, by default it's "closed" and it's their property. If you take that code and use it when there's no permission, that's stealing. If you want to "open" up your code so anyone can use it, you should explicitly tell people they can take it for free. Meet license.

[rer]

Sentences are creations. Does this mean every sentence we write on HN or say to each other by default is closed and needs a license?

[gus_massa]

Actually yes, but so most sites has some legalese in the TOS and there is also fair use.

IANAL. TINLA. You can probably quote a comment from one HN user, but if you copy all the comments from one "famous" user of HN and write a book with them, then you'll probably get some copyright problems.

[volaski]

Nope, your sentences are not as valuable as you think. Neither is mine. But a great book containing thousands of sentences is valuable enough to to be purchased.