Another question is, who do you call a 'native speaker'? Again, OAL says that a native speaker is one who speaks a language as a first language. I've always considered English as my first language simply because it's the language I'm most fluent in. But in my country English functions as a second language, and as a result I've never considered myself a native speaker of English.
What do mother tongue, first language, and native speaker mean to you? Does culture and society matter? Any random thoughts welcome :)