I used to work at a well known internet company (well, well-known about 10 years ago), and on one occasion, were having a new phone system put in, so whereas we're normally split across about 3 floors (customer service, tech support, sales, etc) we were in fact sitting next to each other, all on the one floor...
One Timmy Mallet rang up and was not getting on well with the CS rep who answered his call, but was eventually asked to be put through to Tech support. Now bear in mind we were normally on a different floor, so when the CS rep put him on hold the rep said really loudly "I've got Timmy Mallet on the line and he's a complete tosser" - not realising that someone NEXT TO HIM had already picked up the call, and he'd heard it all... hahahaha....
well, serves him right for annoying the CS rep...