I was never sure if it was a strict rule. Now that it was mentioned I do think I've heard the "federal law" line about remaining in your cabin. Normally I don't care if a person comes up and uses the F lav. But the grouping I found very annoying. A couple decided they liked the view out the 1AB window and were leaning over people to look and point at stuff which I sorta found rude. I don't believe coach beverage was still going on but not positive.