I don't have any problem with it, it's just a boob with a baby attached. Some Americans seem to only see nudity as always being of a sexual context and as a result always obscene. Nudity is a fairly natural thing, we're all naked at least once every couple of days (showers, baths, changing underwear, etc) so I don't see why folk make such a big deal about it. If you are offend, just don't look. Most mothers I've seen doing it, don't draw attention to it and tend to go for seats in corners anyway.