You'll have to check this one, which will never make your connection in Frankfurt. It's often down to the mood of the person at the gate - or your management style. Carry-on luggage looks like being a hot issue in 1998. Most people agree that hand baggage has gotten out of hand. Apart from being a nuisance to other people, excess cabin baggage is a safety hazard.
Some people use bags as a battering ram to reach their seats.
Sitting in the aisle of a crowded 737 you risk being thumped in the face by swinging shoulder bags or your ankles scythed by pull-along luggage. Clearly, what's driving this is that it's a seller's market. The problem is that rules vary widely by carrier, class of travel, type of plane and how heavily a flight is booked, which adds to bewilderment, confusion and apoplexy at check-in. You may end up last on board a crowded flight with nowhere to stow your one legitimate bag. We're waiting for the FAA to make a ruling.