...When they introduced technology to replace employees.
In particular self serve checkouts - I mean these bays have four checkouts here in my little town in the supermarket. Take 4 check out staff and put the favorite as the "lookout" at these self service units and whoosh there goes three jobs...well not necessarily, they might put them elsewhere in the store, but ultimately they don't need to employ someone new, the machine has replaced them. Sure the machine needs maintenance but c'mon that's different.
Same as banks and paying bills...I used to hate going in to pay bills, and then I started to transfer funds electronically...no more waiting in line, no more short staffed facilities because they're out at lunch (yeah, at the same time everyone else is off for lunch and want to pay their bills), no more business hours, no more cash handler mistakes (I hope!).
My local library now has these self checkout systems like the supermarkets, ebooks are becoming popular...have you seen those vending machines that have the DVD's inside? How about those paid services where you pay to rent a movie and it's delivered to your door then you forward it on. Everything anyone would want is pretty much on demand and less and less people are needed to do anything because the processes are so automated and efficient. I think it's great because I hate work, but people need money, and you have to work for that - So what's going to happen?
What happened when telephone switches became automated? When digital photos took over film?
The world sure is changing fast, I'm glad I'm up for the show...things are getting exciting.
I know there must be a lot more examples, feel free to put them in the comments section.