Without a bit more context it's unclear that it was this bad. It sounds like the removed it for one day and then put it back in. This may have been the only way to effectively notify people still relying on it.
We had a deprecated server that we wanted to decommission. We announced this to the entire company. We pointed everyone to the new server, and asked for feedback if it couldn't fulfill any needs that the previous one did not &c. &c. We announced the date the server was going down. We inspected logs and guessed who might still be using it from IP addresses (one of the many reasons for wanting to deprecate the server was there was a single shared login for everyone using it :/)
Finally, on the announced date, we just unplugged the Ethernet cable and got contacted by several different people freaking out, wanting to know what happened to the server. We (as planned) plugged the cable back in and then asked them the same questions that had gone out globally. A month later the server was finally offline for good.
One way of interpreting this is that we unplugged the cable to "send a message" but we obviously did discuss the deprecation with lots of people ahead of time.
I too have learned the value of "turn it off and see who complains" as a last-ditch effort at determining who is still using something and why. It is remarkably effective. However, in at least one case it did take almost an entire week for someone to notice and complain.
This method caused a $10 million dollar, 10 hour long outage at a previous company. You should probably consider who will be complaining in the risk analysis before doing it ;P
There’s honestly no other way to do it. We did this way back when with TLS 1.1 depreciation. We couldn’t use “has anyone connected with TLS 1.1” because all that told us was someone had support for 1.1, not if they could support 1.2. So we turned it off intermittently with increasing frequency to try and generate support tickets.
We had a deprecated server that we wanted to decommission. We announced this to the entire company. We pointed everyone to the new server, and asked for feedback if it couldn't fulfill any needs that the previous one did not &c. &c. We announced the date the server was going down. We inspected logs and guessed who might still be using it from IP addresses (one of the many reasons for wanting to deprecate the server was there was a single shared login for everyone using it :/)
Finally, on the announced date, we just unplugged the Ethernet cable and got contacted by several different people freaking out, wanting to know what happened to the server. We (as planned) plugged the cable back in and then asked them the same questions that had gone out globally. A month later the server was finally offline for good.
One way of interpreting this is that we unplugged the cable to "send a message" but we obviously did discuss the deprecation with lots of people ahead of time.