Talmid: Who here is saying that? With all the arguments going on here on this thread, the one thing we ALL agree on is that Reb Moshe assur’d the Manhattan and Brooklyn eruvin. The discussion has seemed to have turned to whether or not you can rely on other poskim who disagreed. Everybody knows Reb Moshe’s shittah on this matter; it’s extremely common knowledge.
Gaon: The point about how accepted Reb Moshe’s psak was is as simple as this: name one non-MO Rabbi TODAY who told you you can carry in Manhattan. Not presumptions on what Rabbis in 19th century Warsaw would have said on the matter. The common practice in the frum velt is to go like Reb Moshe on this halachah; that fact that common practice doesn’t go like him in other areas proves absolutely nothing.