Here's what my dad said happened on AC546 YYC-LAS on Thursday. It was overbooked; this is not news... but he is a frequent traveler and said it was the most irate sequence of PA's he's ever heard from an AC agent.
So the first announcement was relatively mild, she somewhat nicely asked if there was a single volunteer who would be willing to give up their seat. No one offered. Next PA added the amount of retribution: $800 in travel vouchers and overnight accommodation. Still no offers. On her third PA, she said the reason they needed the seat was because a crew member (didn't say FA or pilot) needed to get down to LAS to operate a YUL flight. The PA's were becoming increasingly hostile, and on her fourth PA she said, "if nobody volunteers, WE ARE NOT GOING ANYWHERE because this crew member needs to get to Las Vegas and I am not cancelling the Montreal flight." No offers. In her final PA, she says the person who last booked the flight would be bumped and re-accommodated. Finally a lady offered, he's unsure if she had to because she was last on the list, or if she volunteered. The lady was told her tentative routing the following day would be YYC-DEN-SFO-LAS.

Flight was late as a result of these shenanigans.