Last November I flew from Seattle to Venice with my brother and sister inlaw. When we checked in in Seattle they weighed my carry on bag but not my back pack, no issues. On the return flight my bags weighed in no problem 5 pounds under limit (she weighed my carry on bag and my backpack). My brother's bag was 3 pounds to heavy, my sister inlaw bag was under weight.
You would not believe it, but the counter clerk at Lufthanas made a big deal of it. She knew we were all traveling together (all the same last name) and over all we were under weight but she was going to charge my brother for being 3 pounds over. We ended up taking a few pounds out of his bag and putting them into my bag. What is the difference, all the bags went on the same plane ? combined bags still weighed the same.......So why the hassle of shifting 3 pounds of laundry ?
This was also the first time that my Granola bars had to be taken out of my back pack and inspected including a swab of the zip lock baggie I had them in. This was done both in Seattle and in Venice. Security is stepped up in airports.