I think it is absolutely the FA’s role to enforce correct usage of carry-on space. The arguments tend to happen, in my experience, when fellow passengers try to confront one of these “overhead space hogs”
=============================================================

Your opinion is NOT shared by most flight attendants. Carry-on space is just that, carry-on space. There is NO RULE that requires you to place any item anywhere, other then a safety issue that you must abide by. Your bag can not inhibit egress into the aisle in the event of an emergency.
MarkieA, please search any airline site, the FAA site, any site that would support your opinion, OTHER THEN, the flight attendants are there to ensure that carry on items are STOWED SAFELY.
A flight attendant trying to remove a passenger from a flight, must involve the Captain, it’s HIS decision, not a flight attendants. And said, F/A better have a good excuse because LAWSUITS occur and/or airline legal departments get involved.

Welcome to a new feature on Bing Travel – Blinks. Blinks are the Bing editors’ favorite links…

I think it is absolutely the FA’s role to enforce correct usage of carry-on space. The arguments tend to happen, in my experience, when fellow passengers try to confront one of these “overhead space hogs”. However, I have rarely seen an FA-enforced rule – or courtesy – develop into an argument. After all, if you argue with an FA, you’re likely to be removed from the plane for interfering with National Security or some such.