Why do people discriminate against moslem?

I'm a moslem and i'm indonesian. When I use hijab on my yahoo avatar with mecca background on yahoo,and i asking a question about a famous person,people just said "You're a moslem girl,so why did you care about christian?" In my country,girls being friend with boys are allowed. Girls can go out late too (But they're not allowed to do anything bad). So why did they still disciminate me? I'm not a terrorist as everyone knows