Definitely Trading Standards (or here in Ireland the NSAI) would be very interested...
Once funny incident I personally had was where my suitcase was 2kg over and I was asked (ordered!) to lighten it - which I did by transferring some items to my carry on.
The desk agent was happy now that his baggage was within weight, but I was amused to explain to the wife that because I was still carrying on the excess nothing had actually changed.
A case of "my bit is OK" (and a thank you to Mr.Boeing's 757's nicely over-power engines!!)
Darragh