Yes, the default is "SafeSearch" enabled. Bing and Google filter for everyone... it's not opt-in. You opt-out, as would people living in "strict markets".
I don't believe bing/google are required by law in the U.S. to do this (correct me if I'm wrong)... so the e.f.f. arguments are a bit hypocritical by not including, essentially, the rest of the world.