[knodi123]

> I have a (maybe naive) question: why is the person draining ETH from DAO called "attacker"?

It's just a philosophical distinction. Suppose someone who had never built a software program in his life, successfully got a patent for "online marketplace for smartphone apps", and then went and successfully sued random weak-looking people for uploading their apps to the google play store.

Obviously he's abusing the system, and obviously he's a parasite preying on the weak with zero moral justification, in a way that threatens the very foundation of the tech industry... But what he's doing is not illegal; he's just exploiting a flaw.

Is he an attacker?

/shrug

Depends on how you define things, but the context makes the meaning clear in this case, I think.