It could also be a general question; say, a Brazilian making a statement meaning a question or vice versa.
It could be a (news) item in a newspaper questioning the general notion that Brazilian like soccer as in (or meaning) "Is it true that all Brazilians like soccer?
So, the answer could be short, yes or no. And the answer could be some kind of elaborated answer (to illustrate - the news item or some piece of text from some student, etc).
And finally, you could take it as being a direct question, as Zumstein post exemplifies very well. The type of question that would mean "what about you? What do you think? Do we like soccer? [(you - for instance, do you like it?"]